Week of Monday, August 24

This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Monday, August 24.  All times are given as local St. Louis time (Central Daylight Time).  For definitions of terminology used in the night sky update, click the highlighted text. 

Information updated weekly or as needed. 

Join us for our next star party, Friday, September 4, 2015 held in association with the St. Louis Astronomical Society.  For details, see the information at the bottom of this page. 

The Sun and the Moon 

Sunrise is at 6:23 a.m. on Monday, August 24 and sunset is at 7:43 p.m. providing us with a bit more than 13 hours of daylight.  Even after sunset, the light from the Sun will still dimly illuminate our sky for about 1.5 hours.  This period of time is called twilight, which ends around 9:18 p.m. this week.  For those with a sun dial, solar transit or local noon occurs around 1:03 p.m. this week. 

      

Day

Sunrise

Sunset

24 Aug

6:23 a.m.

7:43 p.m.

25 Aug

6:24 a.m.

7:42 p.m.

 26 Aug

6:25 a.m.

7:40 p.m.

 27 Aug

6:26 a.m.

7:39 p.m.

 28 Aug

6:26 a.m.

7:37 p.m.

 29 Aug

6:27 a.m.

7:36 p.m.

 30 Aug

6:28 a.m.

7:34 p.m.

 31 Aug

6:29 a.m.

7:33 p.m.

 01 Sep

6:30 a.m.

7:31 p.m.

           

Moonrise for Monday, August 24 occurs at 3:33 p.m. and moonset will occur at 1:52 a.m. on the following day.  On Monday, August 17 the Moon will be exhibiting a waxing gibbous phase with 69% of the lunar disk illuminated.  Full moon occurs on August 29.  The full moon for August is called the Full Sturgeon Moon.  Also on this night the Moon will reach perigee.  This is when the Moon is at its closest to the Earth and may look a little bit bigger.  Perigee occurs once every lunar cycle (orbit).  

International Space Station (ISS) Observing 

There are no visible passes of ISS over St. Louis this week.  ISS is transitioning from evening pass to morning passes and will not be seen again until September 5.  Since ISS is not visible this week we will list a few of the visible passes of the Chinese space station Tiangong 1 below.  

Catch Tiangong 1 flying over St. Louis in the evening hours starting Monday, August 24.  

Date

Mag

Starts

Max. altitude

Ends

Time

Alt.

Az.

Time

Alt.

Az.

Time

Alt.

Az.

26 Aug

 0.9

20:33:12

10

WSW

20:36:19

82

SSE

20:39:01

13

ENE

28 Aug

 1.3

20:05:27

10

WSW

20:08:34

68

NNW

20:11:40

10

ENE 

Magnitude (Mag): The Measure of brightness for a celestial object.  The lower the value is, the brighter the object will be. 

Altitude (Alt):  The angle of a celestial object measured upwards from the observer’s horizon. 

Azimuth (Az):  The direction of a celestial object, measured clockwise from an observer’s location with north being 0°, east being 90°, south being 180° and west being 270°. 

For information about ISS flyovers and other visible satellites, visit www.heavens-above.com 

Detailed information regarding all unmanned exploration of our universe, missions past, present, and planned, can be found at Jet Propulsion Laboratories:

http://www.jpl.nasa.gov/ 

The Planets Visible Without A Telescope

Mars

The Red planet is now climbing out of the Sun’s glare rising at 4:37 a.m.  By 5:30 Mars will be about 10 degrees above the horizon shining with an apparent magnitude of 1.9.  Early risers may have a chance to see Mars but you might need to use binoculars as twilight will have already started.  Mars will continue to climb higher in our sky as we approach May 22, 2016 which is the next Opposition of Mars.  Mars is back and getting better once again.  

Saturn

Saturn has reached opposition and will now rise before the Sun sets.  Due to the angle of the ecliptic Saturn will remain low in the southwestern sky.  Look for the ringed planet about 40 minutes after sunset low in the southern sky.  Saturn will set by 11:35 p.m.     

Messier Object of the Week

For the last few years the night sky update included a section that highlighted one constellation a month and a few objects of interest inside of it.  Unfortunately of the 88 constellations there are only about 60 we can see in St. Louis and of these there are only so many that have enough objects to reference that would interest both beginners and advanced observers.  So in 2015 we will change things a bit for this section and instead of highlighting one constellation for each month we will highlight one Messier object a week using the Astronomical League’s Binocular Messier program as our guide.  

The Astronomical League is an amateur astronomy society that is composed of over 240 local amateur astronomy societies across the United States and includes members at large and other supporting members.  Their goal is to promote the science of astronomy through education, incentive and communication.  

One of the many ways the Astronomical League has assisted amateur astronomers around the world is by creating various observing programs that highlight different aspects of astronomy and how an amateur astronomer can observe the sky and learn more about astronomy in doing so.  Some of these programs are introductory and are targeted at those beginning to learn about observational astronomy and some are extremely advanced, require specialized equipment and require a large amount of time to complete.  These observing programs cover most any type of object or way to observe the sky so everyone should be able to find one that matches their interests and abilities.  It is important to note that these programs are not part of any class or lecture series but are rather lists of objects that highlight types of objects or observing methods relevant to astronomy.  Taking part in these programs is done under one’s own choice.  To officially complete each program you do have to be a member of the Astronomical League but you do not have to join to use them as observing guides or education tools.  I would urge anyone interested in astronomy to look at these programs as they will help organize observing sessions and will help refine observing skills you already have.  You can find out more information about the Astronomical League’s observing programs here https://www.astroleague.org/observing.html 

The observing program we will use to help guide us through the 2015 observing year is the Binocular Messier Program.  This is a program that will appeal to both beginning and advance observers.  Too often it is thought that you need to have a telescope for astronomical observations.  Telescopes make great observing tools and yes they can show you more than binoculars but they do have their limitations.  Cost, size, weight and complexity will often be a surprise to people when they first learn about telescopes.  These factors can keep people from using telescopes they own or from buying one at all.  The best advice to follow is a good observing tool is one you will use.  

The binocular observing program is an introduction to the Messier catalog.  The Messier catalog was created by French astronomy Charles Messier.  He was a comet hunter that would periodically find objects that could be confused for comets.  To help others avoid these objects when looking for comets he created a list that consists of objects that today we know are star clusters, nebula and galaxies.  The Messier catalog is a great introduction to deep sky observing for northern hemisphere observers and as such it will be our guide for each week of 2015.  Each week we will highlight a Messier object that is part of the Astronomical League’s binocular Messier program.  I would urge each observer to fulfill the requirements of the program even if you do not intend to join the League for completion.  The requirements involve logging observing data that can help refine observing skills that will be useful later down the road.  If you have an interest in astronomy and learning more about observational astronomy I would also recommend checking out one of the two excellent astronomy societies near St. Louis.  Both are members of the Astronomical League and both do numerous public observing nights around town.  These clubs are the

St. Louis Astronomical Society and

Astronomical Society of Eastern Missouri

If you do not live in the St. Louis, Missouri area chances are you have similar astronomical societies where you live.  

The Messier object for the week of August 3 is the emission nebula Messier 17 (M17).  Emission nebulae are the stellar nurseries of galaxies.  The hot glowing hydrogen gas we observe is being excited by the young hot stars inside of them.  In these stellar cocoons dust and gas are collapsing into what will be a future stars.  The stars that have already formed ionize the hydrogen in the clouds causing them to emit a telltale pinkish red color.  This excitation is the same process that allows us to see auroras and neon signs. 

M17 is found about 5,000 light years from Earth in the Sagittarius-Carina arm of the Milky Way galaxy.  At this distance it shines with an apparent magnitude of 6.0. To locate M17 first locate the Teapot asterism we have been using over the last number of weeks.  From the top of the teapot scan about 10 degrees north and you will see a dim fuzzy patch of light which is M17.  Follow the link below of help in finding M17.

http://www.iau.org/static/public/constellations/gif/SGR.gif         

The Messier object for the week of August 10 is Messier 34 (M34).  M34 is an open galactic star cluster that contains nearly 100 stars.  These stars are estimated to be about 180 million years old and are found about 1,400 light years away.  At this distance the stars in this cluster shine collectively as a 5.5 magnitude object that is easily observed in binoculars.  

M34 is part of a local group of stars clusters that likely formed from the same complex.  The Pleiades, Alpha Persei, and Delta Lyrae star clusters share similar origins and are moving through space together.  To find M34 first look for the W-shape of the constellation Cassiopeia.  She can be found rising in the northeast around 10:00 p.m.  Follow the stars Gamma and Delta Cass to the south and you will be in Perseus.  From here locate the variable star Algol (Beta Persei) and look about 10 degrees to the east and you will spot an X-shape of stars which is M34.  Use the maps below for help in locating the M34 and the guide stars mention above. 

http://www.iau.org/static/public/constellations/gif/PER.gif

http://www.iau.org/static/public/constellations/gif/CAS.gif 

The Messier object for the week of August 17 is the Open star cluster Messier 103 (M103).  M103 is an open star cluster that lies about 8,500 light years away towards to the Perseus arm of the Milky Way.  It is one of the more distant open star clusters visible.  At 8,500 light years away M103 has an angular diameter of 6 minutes and shines with an apparent magnitude of 7.4.  M103 is thought to have anywhere from 70 to 126 stars most of which will be too dim to see with binoculars.  The brightest members are about 10.5 magnitude meaning they will only be seen in large binoculars.  

M103 is located in the W-shaped constellation Cassiopeia.  She is easy to find after 10:00 p.m. rising in the northeast sky.  To find M103 you have to locate the bright star Delta Cass.  From Delta Cass look about one degree to the northwest and you will see a dim fuzzy patch of light with a few bright stars in front of it.  The brightest is a nonmember double star called Struve 131.  Most of the stars in M103 are hot Blue white stars but in its center is a bright red giant star.  Finding M103 is pretty simple but seeing it is another story.  In our city lights the dim patch of light can be difficult but it is doable.  If you have trouble seeing M103 try using your averted vision and you should be able to spot it.  Use the map below for assistance. 

http://www.iau.org/static/public/constellations/gif/CAS.gif 

The Messier object for the week of August 24 is the open star cluster Messier 23 (M23).  This open cluster is about 2,100 light years away.  At this distance the roughly 150 stars in M23 shine with an apparent magnitude of 6.9.  M23 is thought to be one of the older open star clusters we can see with its member stars being about 300 million years old. 

Finding M23 is relatively easy as it is located above the teapot shape of Sagittarius.  To find Sagittarius look for the Summer Triangle overhead around 10:00 p.m.  Follow the triangle shape to the south and you will find the teapot shape of Sagittarius.  Once Sagittarius is in view look about seven degrees north of the teapot’s lid and the bright star Mu Sagittarii will be visible.  Once you can see Mu Sagittarii look about six degrees to the northeast and there will be a close scattering of stars that covers about 27 arc minutes of sky which is M23.  At first it will look like a few bright stars close together but with further viewing you will notice a dim nebulous patch of light.  Use the map below for assistance in finding M23.

http://www.iau.org/static/public/constellations/gif/SGR.gif               

Our next Star Party will be held on Friday, September 4, 2015, from dusk until 10 p.m. 

As part of the Saint Louis Science Center’s First Fridays, weather permitting, the St. Louis Astronomical Society and the Science Center will set up a number of telescopes outdoors and be on-hand to answer your questions.  Telescope viewing begins around 8 p.m.  Regardless of the weather on September 4, join us indoors in our planetarium theater for “The Sky Tonight”.  Showtime is at 7 p.m.   

This free, indoor star program will introduce you to the current night sky, the planets, and the seasonal constellations. Doors open 15 minutes before show time. Shows begins at 7 p.m. Sorry, no late admissions due to safety issues in the darkened theater.  

The St. Louis Astronomical Society helps host the monthly Star Parties at the Saint Louis Science Center which are held on the first Friday of each month. Our Monthly Star Parties are open to the public and free of charge.  For more information about the St. Louis Astronomical Society visit their website at www.slasonline.org

Miles from Tomorrowland

Calling all Cosmic Explorers! Disney Junior and the St. Louis Science Center invite you to the Miles From Tomorrowland Space Missions experience. Join us in the Discovery Room and explore tech, vehicles and planets with fun mission activities every day this summer starting July 20th – August 31st. Join us for a blastastic time!

Plus, you can submit a photo of your child’s activity online for a chance to win the XPRIZE Superstellar Blast Off Experience including: a VIP family trip to the Kennedy Space Center to see a rocket launch and meet an astronaut. Winners will also receive a virtual reality viewer, 3D printer and Miles From Tomorrowland toys!  Visit DisneyJunior.com/SpaceMissions for more information. 

 

NO PURCHASE NECESSARY. Void where prohibited. Open to persons who are, as of entry, 18 years of age or older, or the age of majority, whichever is older, and legal residents of, and physically located within, the 50 United States or D.C. Limit one (1) Submission per Member per day. Contest begins at 12:01 AM (PT) on July 15, 2015, and Submissions must be received by 11:59 PM (PT) on August 31, 2015. Click here for Official Rules for full eligibility and entry details. 

Week of Monday, May 11

This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Monday, May 11.  All times are given as local St. Louis time (Central Daylight Time).  For definitions of terminology used in the night sky update, click the highlighted text. 

Information updated weekly or as needed. 

Join us for our next star party, Friday, June 5, 2015 held in association with the St. Louis Astronomical Society.  For details, see the information at the bottom of this page. 

The Sun and the Moon 

Sunrise is at 5:53 a.m. on Monday, May 11 and sunset is at 8:02 p.m. providing us with over 14 hours of daylight.  Even after sunset, the light from the Sun will still dimly illuminate our sky for about 1.75 hours.  This period of time is called twilight, which ends around 9:47 p.m. this week.  For those with a sun dial, solar transit or local noon occurs around 12:57 p.m. this week.      

Day

Sunrise

Sunset

11 May

5:53 a.m.

8:02 p.m.

12 May

5:52 a.m.

8:03 p.m.

13 May

5:51 a.m.

8:04 p.m.

14 May

5:50 a.m.

8:05 p.m.

15 May

5:49 a.m.

8:06 p.m.

16 May

5:49 a.m.

8:07 p.m.

17 May

5:48 a.m.

8:08 p.m.

18 May

5:47 a.m.

8:08 p.m.

           

Moonrise for Monday, May 11 occurs at 1:42 a.m. and moonset will occur at 12:55 p.m.  On Monday, May 11 the Moon will be exhibiting a last quarter phase with about 50% of the lunar disk illuminated.  New moon is on Monday, May 18.  

International Space Station (ISS) Observing 

Visible passes of ISS this week occur during the morning hours.  The best of these occur on May 14 and 17.  Use the table below for more information. 

Catch ISS flying over St. Louis in the morning hours starting Monday, May 11. 

Date

Mag

Starts

Max. altitude

Ends

Time

Alt.

Az.

Time

Alt.

Az.

Time

Alt.

Az.

12 May

-2.0

05:05:52

10

SSW

05:08:49

33

SE

05:11:48

10

ENE

13 May

-1.1

04:14:00

14

SSE

04:15:10

16

SE

04:17:19

10

E

14 May

-3.4

04:54:56

16

SW

04:57:28

85

SE

05:00:44

10

NE

15 May

-2.5

04:03:13

35

SSE

04:03:41

38

SE

04:06:44

10

ENE

16 May

-0.7

03:11:24

14

E

03:11:24

14

E

03:12:18

10

E

16 May

-2.5

04:43:56

17

W

04:46:07

41

NNW

04:49:13

10

NE

17 May

-3.5

03:52:01

80

W

03:52:09

84

NW

03:55:25

10

NE

18 May

-1.0

03:00:01

21

ENE

03:00:01

21

ENE

03:01:22

10

ENE

18 May

-1.4

04:32:33

12

WNW

04:34:46

22

NNW

04:37:24

10

NNE 

Magnitude (Mag): The Measure of brightness for a celestial object.  The lower the value is, the brighter the object will be. 

Altitude (Alt):  The angle of a celestial object measured upwards from the observer’s horizon. 

Azimuth (Az):  The direction of a celestial object, measured clockwise from an observer’s location with north being 0°, east being 90°, south being 180° and west being 270°.  

For information about ISS flyovers and other visible satellites, visit www.heavens-above.com 

Detailed information regarding all unmanned exploration of our universe, missions past, present, and planned, can be found at Jet Propulsion Laboratories:

http://www.jpl.nasa.gov/ 

The Planets Visible Without A Telescope

Mercury

The closest planet to the Sun is once again briefly visible in the evening sky.  Look for it about 30 minutes after sunset low in the west.  Mercury will set by 9:43 p.m.  Mercury reaches maximum eastern elongation on May 7.  After this date Mercury will rapidly head back into the glare of the Sun.  You have about one week to look for Mercury before the Sun’s glare washes it out from view.

Venus

The second planet from the Sun is out of the glare of the Sun and will be visible shortly after sunset.  Venus will be seen about 20 minutes after sunset low in the southwest and will set by 11:34 p.m.  Venus will continue to climb above the western horizon until June 6 when it reaches maximum eastern elongation.  After this Venus will begin to head back into the glare of the Sun. 

Jupiter

The largest planet in the solar system has returned to our evening skies.  Jupiter is now rising before the Sun sets and as such will be visible about 20 minutes after sunset in our eastern skies.  Jupiter is currently located in the constellation Cancer the Crab and will set by 1:51 a.m. 

If you keep track of Jupiter once a week through July you will notice what is called retrograde motion.  This is cause as we catch up with a planet in our orbit and then pass it by.  This will make the planet look like it stops and then moves in the opposite direction.  This is due to the changing angles we see Jupiter with respect to the background star field.  Jupiter right now is exhibiting a western motion and by July will have returned to its eastern motion.  This type of motion is what ancient astronomers noticed that lead them to name the planets Aster Planetes or wandering stars. 

Saturn

Saturn has broken the midnight threshold and now rises in the late evening hours.  Due to the angle of the ecliptic Saturn remains low in the south sky reaching its greatest altitude around 2:00 a.m.  Saturn rises at 8:47 p.m. but you will have to wait until near 10:30 p.m. to get a decent view of the ringed planet.  Saturn will rise about 30 minutes earlier than it did the week before as it approaches opposition on May 22, 2015.  

Messier Object of the Week

For the last few years the night sky update included a section that highlighted one constellation a month and a few objects of interest inside of it.  Unfortunately of the 88 constellations there are only about 60 we can see in St. Louis and of these there are only so many that have enough objects to reference that would interest both beginners and advanced observers.  So in 2015 we will change things a bit for this section and instead of highlighting one constellation for each month we will highlight one Messier object a week using the Astronomical League’s Binocular Messier program as our guide.  

The Astronomical League is an amateur astronomy society that is composed of over 240 local amateur astronomy societies across the United States and includes members at large and other supporting members.  Their goal is to promote the science of astronomy through education, incentive and communication.  

One of the many ways the Astronomical League has assisted amateur astronomers around the world is by creating various observing programs that highlight different aspects of astronomy and how an amateur astronomer can observe the sky and learn more about astronomy in doing so.  Some of these programs are introductory and are targeted at those beginning to learn about observational astronomy and some are extremely advanced, require specialized equipment and require a large amount of time to complete.  These observing programs cover most any type of object or way to observe the sky so everyone should be able to find one that matches their interests and abilities.  It is important to note that these programs are not part of any class or lecture series but are rather lists of objects that highlight types of objects or observing methods relevant to astronomy.  Taking part in these programs is done under one’s own choice.  To officially complete each program you do have to be a member of the Astronomical League but you do not have to join to use them as observing guides or education tools.  I would urge anyone interested in astronomy to look at these programs as they will help organize observing sessions and will help refine observing skills you already have.  You can find out more information about the Astronomical League’s observing programs here https://www.astroleague.org/observing.html 

The observing program we will use to help guide us through the 2015 observing year is the Binocular Messier Program.  This is a program that will appeal to both beginning and advance observers.  Too often it is thought that you need to have a telescope for astronomical observations.  Telescopes make great observing tools and yes they can show you more than binoculars but they do have their limitations.  Cost, size, weight and complexity will often be a surprise to people when they first learn about telescopes.  These factors can keep people from using telescopes they own or from buying one at all.  The best advice to follow is a good observing tool is one you will use.  

The binocular observing program is an introduction to the Messier catalog.  The Messier catalog was created by French astronomy Charles Messier.  He was a comet hunter that would periodically find objects that could be confused for comets.  To help others avoid these objects when looking for comets he created a list that consists of objects that today we know are star clusters, nebula and galaxies.  The Messier catalog is a great introduction to deep sky observing for northern hemisphere observers and as such it will be our guide for each week of 2015.  Each week we will highlight a Messier object that is part of the Astronomical League’s binocular Messier program.  I would urge each observer to fulfill the requirements of the program even if you do not intend to join the League for completion.  The requirements involve logging observing data that can help refine observing skills that will be useful later down the road.  If you have an interest in astronomy and learning more about observational astronomy I would also recommend checking out one of the two excellent astronomy societies near St. Louis.  Both are members of the Astronomical League and both do numerous public observing nights around town.  These clubs are the

St. Louis Astronomical Society and

Astronomical Society of Eastern Missouri

If you do not live in the St. Louis, Missouri area chances are you have similar astronomical societies where you live.  

The Messier object for the week of May 4 is the globular star cluster Messier 92 (M92).  Continuing our exploration of globular star clusters we will return to the constellation Hercules.  In Hercules we have already covered the great cluster M13.  A bit further north of M13 we will find a lesser known but equally beautiful M92.  Lying at a distance of 26,700 light years M92 shines with an apparent magnitude of 6.4.  It is estimated to have a few hundred thousand stars that are nearly as old as the universe itself.  

Finding M92 is pretty simple but it will be more difficult to see than the previous globular star clusters covered so far.  To find M92 you will have to find the constellation Hercules.  Start by going outside at 10:00 p.m. and look east.  High in the east you should see the bright orange/red star Arcturus in the constellation Bootes.  Once you have found Bootes (kite shape of stars) follow a path down to the eastern horizon.  This path will take you from Bootes, through Corona Borealis (U-shape of stars) and eventually to the bowtie shape of Hercules.  Next find the two northern most stars in the bowtie shape called Eta and Pi Herculis.  From these two stars imagine an equilateral triangle pointing to the north.  M92 will be located near the northern point of the triangle.  M92 is easily seen in binoculars as a diffuse patch of light.  Follow the links below for help in finding M92 and the constellations that will guide you there.

http://www.iau.org/static/public/constellations/gif/HER.gif

http://www.iau.org/static/public/constellations/gif/BOO.gif

http://www.iau.org/static/public/constellations/gif/CRB.gif                      

The Messier object for the week of May 11 is the globular star cluster Messier 12 (M12).  The globular star cluster M12 is located in the constellation Ophiuchus the Serpent Bearer.  Lying at a distance of 16,000 light years it shines with an apparent magnitude of 6.7.  It is estimated to be 12 to 13 billion years old.  Compared to its contemporaries covered so far M12 has lost a number of its stars.  Globular star clusters follow elongated elliptical orbits that take them through dense parts of the Milky Way’s plane.  As globular star clusters orbit the galaxy, gravitation influence from the Milky Way will rip material away from them.  A study using the VLT (Very Large Telescope) has shown that M12 has lost most of its low mass stars to the Milky Way.  

Visually M12 will appear less dense than most of its globular companions.  Due to this M12 will be a good globular cluster to introduce how these ancient star clusters are classified.  As with all objects creating ways to classify them helps scientists study the processes involved with them.  The system used for globular star clusters is called the Shapley-Sawyer Classification System.  This system was started by astronomers Harlow Shapley and Helen Sawyer Hogg.  It is a system that classifies globular star clusters based on how concentrated their cores are.  They are numbered 1 through 12 using Roman numerals with (I) being a highly concentrated core and (XII) being a core with almost no concentration.  M12 is a class IX cluster meaning it appears loose near the core. 

To find M12 you will need to locate Ophiuchus in your southern sky.  To do this first locate the constellation Hercules.  Like last week to do this you will use the Big Dipper to locate Bootes and from there look to the east for a bowtie shape which will be Hercules.  Refer last week’s Messier object M92 to revisit the details on how to do this.  Once you have found the bowtie move south until you hit the bright orange/red star Antares in Scorpius.  The area between Hercules and Scorpius is where you will find Ophiuchus.  Once you have found this area you need to locate the star Delta Ophiuchi.  From this star you then look about 8.5 degrees to the east and you will find M12.  M12 will appear as a nebulous patch of light through binoculars.  Use the maps below to help you identify M12 and the other objects referenced above.

http://www.iau.org/static/public/constellations/gif/OPH.gif

http://www.iau.org/static/public/constellations/gif/UMA.gif

http://www.iau.org/public/themes/constellations/#boo

http://www.iau.org/public/themes/constellations/#her

http://www.iau.org/static/public/constellations/gif/SCO.gif  

Our next Star Party will be held on Friday, June 5, 2015, from dusk until 10 p.m. 

Weather permitting, the St. Louis Astronomical Society and the Science Center will set up a number of telescopes outdoors and be on-hand to answer your questions.  Telescope viewing begins around 8 p.m.  Regardless of the weather on June 5, join us indoors in our planetarium theater for “The Sky Tonight”.  Showtime is at 7 p.m. 

This free, indoor star program will introduce you to the current night sky, the planets, and the seasonal constellations. Doors open 15 minutes before show time. Shows begins at 7 p.m. Sorry, no late admissions due to safety issues in the darkened theater.  

The St. Louis Astronomical Society helps host the monthly Star Parties at the Saint Louis Science Center which are held on the first Friday of each month. Our Monthly Star Parties are open to the public and free of charge.  For more information about the St. Louis Astronomical Society visit their website at www.slasonline.org

Genome: Unlocking Life's Code

It is in every living thing on Earth. It is the complete set of instructions that is needed for every living thing to grow and function. It can help you unlock the secrets of your past and reveal the path to your future. It is the genome! 

Week of Monday, March 9

This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Monday, March 9.  All times are given as local St. Louis time (Central Daylight Time).  For definitions of terminology used in the night sky update, click the highlighted text. 

Information updated weekly or as needed. 

Join us for our next star party, Friday, April 3, 2015 held in association with the St. Louis Astronomical Society.  For details, see the information at the bottom of this page. 

The Sun and the Moon 

Sunrise is at 7:22 a.m. on Monday, March 9 and sunset is at 7:02 p.m. providing us with nearly 12 hours of daylight.  Even after sunset, the light from the Sun will still dimly illuminate our sky for about 1.5 hours.  This period of time is called twilight, which ends around 8:30 p.m. this week.  For those with a sun dial, solar transit or local noon occurs around 1:12 p.m. this week. 

      

Day

Sunrise

Sunset

09 Mar

7:22 a.m.

7:02 p.m.

10 Mar

7:20 a.m.

7:03 p.m.

11 Mar

7:19 a.m.

7:04 p.m.

12 Mar

7:17 a.m.

7:05 p.m.

13 Mar

7:16 a.m.

7:06 p.m.

14 Mar

7:14 a.m.

7:07 p.m.

15 Mar

7:13 a.m.

7:08 p.m.

16 Mar

7:11 a.m.

7:09 p.m.

          

Moonrise for Monday, March 9 occurs at 10:53 p.m. and moonset will occur at 9:52 a.m. on the following day.  On Monday, March 9 the Moon will be exhibiting a waning gibbous phase with about 86% of the lunar disk illuminated.  Last quarter moon occurs on March 13.   

International Space Station (ISS) Observing 

Visible passes of ISS from St. Louis this week occur during the morning hours.  The best of these passes are on the mornings of March 12 and 14.  Use the table below for information on when and where to look for ISS this week. 

Catch ISS flying over St. Louis in the morning hours starting Monday, March 9.  

Date

Mag

Starts

Max. altitude

Ends

Time

Alt.

Az.

Time

Alt.

Az.

Time

Alt.

Az.

10 Mar

-1.7

06:09:45

10

SSW

06:12:38

31

SE

06:15:33

10

ENE

11 Mar

-0.8

05:19:19

15

SE

05:19:44

15

SE

05:21:47

10

E

12 Mar

-3.4

06:01:27

32

SW

06:02:48

83

SE

06:06:02

10

NE

13 Mar

-1.4

05:10:45

29

E

05:10:45

29

E

05:12:46

10

ENE

13 Mar

-1.9

06:43:31

10

W

06:46:14

24

NNW

06:48:56

10

NNE

14 Mar

-2.8

05:52:32

38

NW

05:52:57

40

NNW

05:56:01

10

NE

15 Mar

-1.0

05:01:34

23

NE

05:01:34

23

NE

05:02:57

10

NE

15 Mar

-1.1

06:34:34

10

WNW

06:36:34

15

NNW

06:38:31

10

NNE

16 Mar

-1.6

05:43:06

22

NNW

05:43:06

22

NNW

05:45:40

10

NNE

 

Magnitude (Mag): The Measure of brightness for a celestial object.  The lower the value is, the brighter the object will be. 

Altitude (Alt):  The angle of a celestial object measured upwards from the observer’s horizon. 

Azimuth (Az):  The direction of a celestial object, measured clockwise from an observer’s location with north being 0°, east being 90°, south being 180° and west being 270°. 

For information about ISS flyovers and other visible satellites, visit www.heavens-above.com 

Detailed information regarding all unmanned exploration of our universe, missions past, present, and planned, can be found at Jet Propulsion Laboratories:

http://www.jpl.nasa.gov/ 

The Planets Visible Without A Telescope

Venus

The second planet from the Sun is out of the glare of the Sun and will be visible shortly after sunset.  Venus will be seen about 20 minutes after sunset low in the southwest and will set by 9:34 p.m.  Venus will continue to climb above the western horizon until June 6 when it reaches maximum eastern elongation.  After this Venus will begin to head back into the glare of the Sun. 

Mars

Mars is now in the constellation Pisces and rises before the Sun sets.  Mars will be seen in the southwestern skies about 30 minutes after sunset.  Mars will set by 8:58 p.m.   

Jupiter

The largest planet in the solar system has returned to our evening skies.  Jupiter is now rising before the Sun sets and as such will be visible about 20 minutes after sunset in our eastern skies.  Jupiter is currently located in the constellation Cancer the Crab. 

If you keep track of Jupiter once a week through July you will notice what is called retrograde motion.  This is cause as we catch up with a planet in our orbit and then pass it by.  This will make the planet look like it stops and then moves in the opposite direction.  This is due to the changing angles we see Jupiter with respect to the background star field.  Jupiter right now is exhibiting a western motion and by July will have returned to its eastern motion.  This type of motion is what ancient astronomers noticed that lead them to name the planets Aster Planetes or wandering stars. 

Saturn

Saturn is now well out of the glare of the Sun but it remains an early morning object for the time being.  Saturn rises as 1:11 a.m. but you will have to wait until near 2:00 a.m. to get a decent view of the ringed planet.  Saturn will rise about 30 minutes earlier than it did the week before as it approaches opposition on May 22, 2015.   

Comet C/2014 Q2 Lovejoy

2015 is starting out great for comet observers.  The 4th comet discovered by amateur astronomy Terry Lovejoy is now well placed in the sky for northern hemisphere observers to see it during evening hours.  C/2014 Q2 Lovejoy is a long period comet that before it entered the planetary region took 11,000 years to orbit the Sun.  Due to the gravitational influence of the planets and the Sun once the comet is outbound it will have an orbital period of 8,000 years.  It is currently shining with an apparent magnitude of 6.0.  Comet C/2014 Q2 Lovejoy is now on its way out of the inner solar system and as such will begin to fade.  The comet has now faded to 6th magnitude which it will be difficult to see the comet with small binoculars from light polluted skies.  Larger aperture binoculars should still be good but soon the comet will fade too much even for these   

C/2014 Q2 Lovejoy is currently in the constellation Cassiopeia and will slowly move through the western edge of the constellation until April.  This week you will see C/2014 Q2 Lovejoy pass by the open star cluster called the ET Cluster or NGC 457.  If you would like to learn more about this comet and where you can find it visit http://www.skyandtelescope.com/astronomy-news/observing-news/spot-comet-lovejoy-tonight-122920141/ or visit

http://cometchasing.skyhound.com/comets/2014_Q2.pdf 

Messier Object of the Week

For the last few years the night sky update included a section that highlighted one constellation a month and a few objects of interest inside of it.  Unfortunately of the 88 constellations there are only about 60 we can see in St. Louis and of these there are only so many that have enough objects to reference that would interest both beginners and advanced observers.  So in 2015 we will change things a bit for this section and instead of highlighting one constellation for each month we will highlight one Messier object a week using the Astronomical League’s Binocular Messier program as our guide.  

The Astronomical League is an amateur astronomy society that is composed of over 240 local amateur astronomy societies across the United States and includes members at large and other supporting members.  Their goal is to promote the science of astronomy through education, incentive and communication.  

One of the many ways the Astronomical League has assisted amateur astronomers around the world is by creating various observing programs that highlight different aspects of astronomy and how an amateur astronomer can observe the sky and learn more about astronomy in doing so.  Some of these programs are introductory and are targeted at those beginning to learn about observational astronomy and some are extremely advanced, require specialized equipment and require a large amount of time to complete.  These observing programs cover most any type of object or way to observe the sky so everyone should be able to find one that matches their interests and abilities.  It is important to note that these programs are not part of any class or lecture series but are rather lists of objects that highlight types of objects or observing methods relevant to astronomy.  Taking part in these programs is done under one’s own choice.  To officially complete each program you do have to be a member of the Astronomical League but you do not have to join to use them as observing guides or education tools.  I would urge anyone interested in astronomy to look at these programs as they will help organize observing sessions and will help refine observing skills you already have.  You can find out more information about the Astronomical League’s observing programs here https://www.astroleague.org/observing.html 

The observing program we will use to help guide us through the 2015 observing year is the Binocular Messier Program.  This is a program that will appeal to both beginning and advance observers.  Too often it is thought that you need to have a telescope for astronomical observations.  Telescopes make great observing tools and yes they can show you more than binoculars but they do have their limitations.  Cost, size, weight and complexity will often be a surprise to people when they first learn about telescopes.  These factors can keep people from using telescopes they own or from buying one at all.  The best advice to follow is a good observing tool is one you will use.  

The binocular observing program is an introduction to the Messier catalog.  The Messier catalog was created by French astronomy Charles Messier.  He was a comet hunter that would periodically find objects that could be confused for comets.  To help others avoid these objects when looking for comets he created a list that consists of objects that today we know are star clusters, nebula and galaxies.  The Messier catalog is a great introduction to deep sky observing for northern hemisphere observers and as such it will be our guide for each week of 2015.  Each week we will highlight a Messier object that is part of the Astronomical League’s binocular Messier program.  I would urge each observer to fulfill the requirements of the program even if you do not intend to join the League for completion.  The requirements involve logging observing data that can help refine observing skills that will be useful later down the road.  If you have an interest in astronomy and learning more about observational astronomy I would also recommend checking out one of the two excellent astronomy societies near St. Louis.  Both are members of the Astronomical League and both do numerous public observing nights around town.  These clubs are the

St. Louis Astronomical Society and

Astronomical Society of Eastern Missouri

If you do not live in the St. Louis, Missouri area chances are you have similar astronomical societies where you live.  

The Messier object for the week of March 2 is the open star cluster Messier 44 (M44).  Like last month we are starting off with an easy target for all binoculars.  After observing and reading further on this week’s object you will quickly realize that a simple target can be quite rewarding.  M44 is a group of at least 350 stars that lie at a distance of 577 light years.  This group of young stars is estimated to be 730 million years old.  As would be expected of a cluster this old when its stars are plotted on an H-R Diagram it reveals mostly stars still on their main sequence with a few giant stars, a handful of stars transitioning to their giant phases and a few highly evolved white dwarf stars.  Star clusters like M44 are excellent targets for studying the life cycle of stars.  

M44 shines with an apparent magnitude of 3.7 making it visible to the unaided eye.  Due to this brightness M44 has been known about since ancient times.  When viewed with the naked eye M44 will look like a dim nebulous patch of light.  It was first resolved into individual stars by Galileo who could see a bit over 30 stars.  Today many of our binoculars are more powerful than the telescopes Galileo used so M44 will be a great target for binocular observers.  Using large telescopes nearly 200 of the estimated 350 component stars can be observed. 

Due to its age and proper motion it is believed that M44 may be related to another open star cluster called the Hyades.  With an estimated age of 790 million years and a similar direction of motion it is believed the M44 and the Hyades formed from the same large complex of dust and gas.  If you would like to see the Hyades look for the V-shape of stars near M45 in Taurus the Bull.     

M44 also contains a number of interesting stars.  There are a few stars that contain planetary disks likely indicating planet formation.  There are a few stars that have been discovered to already have planets.  Also of interest might be the eclipsing binary star TX Cancri and the star Epsilon Cancri for its unique spectrum.  The later of these will be more of interest to those that have access to a low resolution spectroscope.  

To find M44 you need to locate the constellation Cancer the Crab.  Cancer will appear as an upside down Y-shape that can be seen in the eastern sky after sunset.  The trouble with the constellation Cancer is most of its stars are no brighter than 4th magnitude.  This means if you observe in light polluted conditions this will be a difficult constellation to see.  The trick to finding the constellation Cancer is to first locate the constellations Gemini and Leo.  These are much brighter and are easily identified by their shapes.  Gemini is a large rectangle above the constellation Orion and Leo has a bright backwards question mark shape just below the Big Dipper.  Once you can find these look between them and there is a relatively sparse patch of sky which is the constellation Cancer.  Once in the vicinity look near the mid-section of this sparse patch of sky and there will be a dim patch of light.  This is the open star cluster M44.  Another way to find M44 is to locate the bright stars Castor and Pollux in Gemini and Regulus in Leo.  About halfway between these stars is where you will find M44.  A third way to find M44 is by locating the planet Jupiter.  Jupiter is currently in the constellation Cancer and if you can spot this planet M44 will be about one binocular field to the right.  Keep in mind that this trick will only work for a short time as Jupiter will leave the constellation Cancer by July of 2015.  Use the maps below and you should have no problem finding M44.

http://www.iau.org/static/public/constellations/gif/CNC.gif

http://www.iau.org/static/public/constellations/gif/LEO.gif

http://www.iau.org/static/public/constellations/gif/GEM.gif 

The Messier object for the week of March 9 is the open star cluster Messier 67 (M67).  Like last week’s object M67 is an open star cluster that is found within the Milky Way galaxy.  Lying at a distance of about 2,700 light years M67 shines with an apparent magnitude of 6.1.  At this magnitude M67 will be considerably dimmer then last week’s star cluster M44.  At 6.1 magnitude M67 will still be an easy target through binoculars however due to light pollution it will not be quite as obvious and may take a bit longer to find.  

M67 is estimated to have at least 500 stars of which nearly 100 of them are similar to the Sun.  The Trumpler Classification for M67 is II, 2, r meaning it is detached form background stars exhibiting a slight concentration of stars, its stars have a moderate range in brightness and it is a rich star cluster.  All of this information seems similar to other open star clusters covered so far however M67 is not like the others.  What makes M67 different is its age.  Most open star clusters will last for a few hundred million years.  Eventually gravitational interactions inside and outside of these open star clusters will cause the star cluster to break apart.  M67 is estimated to have an age between 3.2 billion to 5 billion years making it one of the oldest open star clusters in the Milky Way galaxy that we know of.  Astronomical modeling suggests that only the most massive of these open star clusters will last this long and some estimates suggest that M67 has lost about 90% of its mass due to mass loss and member stars escaping.  

M67 will be simple to find if you located last week’s star cluster M44.  M67 is also located in the constellation Cancer the Crab and can be found about 10 degrees south of M44.  If you have trouble locating M67 another point of reference is the star Alpha Cancri.  The constellation Cancer looks like an upside down Y-shape of stars.  Alpha Cancri represents the eastern branch of the Y-shape.  M67 can be found about 2 degrees west of this star.  Use the map below to help find M67 and remember the first step to finding the constellation Cancer is to first locate the constellations Leo and Gemini.  Between these two bright constellations is a dim patch of sky which is where you should start looking for the upside down Y-shape of the constellation Cancer. 

http://www.iau.org/static/public/constellations/gif/CNC.gif   

Our next Star Party will be held on Friday, April 3, 2015, from dusk until 10 p.m. 

Weather permitting, the St. Louis Astronomical Society and the Science Center will set up a number of telescopes outdoors and be on-hand to answer your questions.  Telescope viewing begins at 7 p.m.  Regardless of the weather on April 3, join us indoors in our planetarium theater for “The Sky Tonight”.  Showtime is at 7 p.m. 

This free, indoor star program will introduce you to the current night sky, the planets, and the seasonal constellations. Doors open 15 minutes before show time. Shows begins at 7 p.m. Sorry, no late admissions due to safety issues in the darkened theater. 

The St. Louis Astronomical Society helps host the monthly Star Parties at the Saint Louis Science Center which are held on the first Friday of each month. Our Monthly Star Parties are open to the public and free of charge.  For more information about the St. Louis Astronomical Society visit their website at www.slasonline.org

Week of Monday, February 2

This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Monday, February 2.  All times are given as local St. Louis time (Central Standard Time).  For definitions of terminology used in the night sky update, click the highlighted text. 

Information updated weekly or as needed. 

Join us for our next star party, Friday, February 6, 2015 held in association with the St. Louis Astronomical Society.  For details, see the information at the bottom of this page. 

The Sun and the Moon 

Sunrise is at 7:06 a.m. on Monday, February 2 and sunset is at 5:24 p.m. providing us with over 10 hours of daylight.  Even after sunset, the light from the Sun will still dimly illuminate our sky for about 1.5 hours.  This period of time is called twilight, which ends around 6:55 p.m. this week.  For those with a sun dial, solar transit or local noon occurs around 12:15 p.m. this week.       

Day

Sunrise

Sunset

02 Feb

7:06 a.m.

5:24 p.m.

03 Feb

7:05 a.m.

5:25 p.m.

04 Feb

7:04 a.m.

5:26 p.m.

05 Feb

7:03 a.m.

5:27 p.m.

06 Feb

7:02 a.m.

5:28 p.m.

07 Feb

7:01 a.m.

5:30 p.m.

08 Feb

7:00 a.m.

5:31 p.m.

09 Feb

6:59 a.m.

5:32 p.m.

          

Moonrise for Monday, February 2 occurs at 4:35 p.m. and moonset will occur at 6:34 a.m. on the following day.  On Monday, February 2 the Moon will be exhibiting a waxing gibbous phase with about 98% of the lunar disk illuminated.  The next full moon occurs on February 3.   

International Space Station (ISS) Observing 

Visible passes of ISS from St. Louis this week occur during the evening hours.  The best of these is on the evenings of February 4 and 7.  Learn more about these passes and others this week in the table below. 

Catch ISS flying over St. Louis in the evening hours starting Monday, February 2.  

Date

Mag

Starts

Max. altitude

Ends

Time

Alt.

Az.

Time

Alt.

Az.

Time

Alt.

Az.

02 Feb

-1.0

19:12:17

10

SSW

19:13:11

16

S

19:13:11

16

S

03 Feb

-1.3

18:21:04

10

SSE

18:22:55

15

SE

18:23:34

14

ESE

04 Feb

-3.4

19:03:27

10

SW

19:06:30

73

S

19:06:30

73

S

05 Feb

-2.5

18:11:20

10

SSW

18:14:20

36

SE

18:16:39

15

ENE

05 Feb

-0.5

19:48:05

10

W

19:49:19

18

WNW

19:49:19

18

WNW

06 Feb

-2.4

18:55:11

10

WSW

18:58:18

42

NNW

18:59:20

31

NNE

07 Feb

-3.3

18:02:32

10

SW

18:05:47

83

NW

18:09:03

10

NE

07 Feb

-0.5

19:40:38

10

WNW

19:41:54

14

NW

19:41:54

14

NW

08 Feb

-1.3

18:47:19

10

W

18:49:56

22

NNW

18:51:43

15

NNE

09 Feb

-2.0

17:54:13

10

W

17:57:15

35

NNW

18:00:17

10

NE

 

Magnitude (Mag): The Measure of brightness for a celestial object.  The lower the value is, the brighter the object will be. 

Altitude (Alt):  The angle of a celestial object measured upwards from the observer’s horizon. 

Azimuth (Az):  The direction of a celestial object, measured clockwise from an observer’s location with north being 0°, east being 90°, south being 180° and west being 270°.  

For information about ISS flyovers and other visible satellites, visit www.heavens-above.com 

Detailed information regarding all unmanned exploration of our universe, missions past, present, and planned, can be found at Jet Propulsion Laboratories:

http://www.jpl.nasa.gov/ 

The Planets Visible Without A Telescope

Venus

The second planet from the Sun is out of the glare of the Sun and will be visible shortly after sunset.  Venus will be seen about 20 minutes after sunset low in the southwest and will set by 7:17 p.m.  Venus will continue to climb above the western horizon until June 6 when it reaches maximum eastern elongation.  After this Venus will begin to head back into the glare of the Sun. 

Mars

Mars is now in the constellation Aquarius and rises before the Sun sets.  Mars will be seen in the southwestern skies about 30 minutes after sunset.  Mars will set by 8:02 p.m.  

Jupiter

The largest planet in the solar system has returned to our evening skies.  Jupiter can be found rising by 5:38 p.m. and will be easily visible by 6:30 p.m. in the eastern sky.  Jupiter can currently be found in the constellation Leo the Lion.  Jupiter will be at opposition on February 6, 2015.  On this day Jupiter will rise as the Sun sets and the giant planet will be at its brightest.     

Comet C/2014 Q2 Lovejoy

2015 is starting out great for comet observers.  The 5th comet discovered by amateur astronomy Terry Lovejoy is now well placed in the sky for northern hemisphere observers to see it most of the night.  C/2014 Q2 Lovejoy is a long period comet that before it entered the planetary region took 11,000 years to orbit the Sun.  Due to the gravitational influence of the planets and the Sun once the comet is outbound it will have an orbital period of 8,000 years.  It is currently shining with an apparent magnitude of 5.0.  Comet C/2014 Q2 Lovejoy is now on its way out of the inner solar system and as such will begin to fade. 

C/2014 Q2 Lovejoy is currently in the constellation Andromeda and will slowly move through the western edge of the constellation until February 19.  If you would like to learn more about this comet and where you can find it visit http://www.skyandtelescope.com/astronomy-news/observing-news/spot-comet-lovejoy-tonight-122920141/ 

Messier Object of the Week

For the last few years the night sky update included a section that highlighted one constellation a month and a few objects of interest inside of it.  Unfortunately of the 88 constellations there are only about 60 we can see in St. Louis and of these there are only so many that have enough objects to reference that would interest both beginners and advanced observers.  So in 2015 we will change things a bit for this section and instead of highlighting one constellation for each month we will highlight one Messier object a week using the Astronomical League’s Binocular Messier program as our guide.  

The Astronomical League is an amateur astronomy society that is composed of over 240 local amateur astronomy societies across the United States and includes members at large and other supporting members.  Their goal is to promote the science of astronomy through education, incentive and communication.  

One of the many ways the Astronomical League has assisted amateur astronomers around the world is by creating various observing programs that highlight different aspects of astronomy and how an amateur astronomer can observe the sky and learn more about astronomy in doing so.  Some of these programs are introductory and are targeted at those beginning to learn about observational astronomy and some are extremely advanced, require specialized equipment and require a large amount of time to complete.  These observing programs cover most any type of object or way to observe the sky so everyone should be able to find one that matches their interests and abilities.  It is important to note that these programs are not part of any class or lecture series but are rather lists of objects that highlight types of objects or observing methods relevant to astronomy.  Taking part in these programs is done under one’s own choice.  To officially complete each program you do have to be a member of the Astronomical League but you do not have to join to use them as observing guides or education tools.  I would urge anyone interested in astronomy to look at these programs as they will help organize observing sessions and will help refine observing skills you already have.  You can find out more information about the Astronomical League’s observing programs here https://www.astroleague.org/observing.html 

The observing program we will use to help guide us through the 2015 observing year is the Binocular Messier Program.  This is a program that will appeal to both beginning and advance observers.  Too often it is thought that you need to have a telescope for astronomical observations.  Telescopes make great observing tools and yes they can show you more than binoculars but they do have their limitations.  Cost, size, weight and complexity will often be a surprise to people when they first learn about telescopes.  These factors can keep people from using telescopes they own or from buying one at all.  The best advice to follow is a good observing tool is one you will use.  

The binocular observing program is an introduction to the Messier catalog.  The Messier catalog was created by French astronomy Charles Messier.  He was a comet hunter that would periodically find objects that could be confused for comets.  To help others avoid these objects when looking for comets he created a list that consists of objects that today we know are star clusters, nebula and galaxies.  The Messier catalog is a great introduction to deep sky observing for northern hemisphere observers and as such it will be our guide for each week of 2015.  Each week we will highlight a Messier object that is part of the Astronomical League’s binocular Messier program.  I would urge each observer to fulfill the requirements of the program even if you do not intend to join the League for completion.  The requirements involve logging observing data that can help refine observing skills that will be useful later down the road.  If you have an interest in astronomy and learning more about observational astronomy I would also recommend checking out one of the two excellent astronomy societies near St. Louis.  Both are members of the Astronomical League and both do numerous public observing nights around town.  These clubs are the

St. Louis Astronomical Society and

Astronomical Society of Eastern Missouri

If you do not live in the St. Louis, Missouri area chances are you have similar astronomical societies where you live.  

The Messier object for the week of February 2 is the open star cluster Messier 45 (M45).  If there is one star cluster that is preferred over all others M45 would likely be the one that many observers would list.  It is bright enough to be seen with the naked eye, individual stars are resolvable through the smallest aperture instruments and due to its close proximity to our solar system it has a wealth of details and information that make it valuable to both professional and amateur astronomers.  

M45 is visible around the world as it is near the plane of the ecliptic.  This is the same path that the planets Sun and Moon appear to follow.  Due to its visibility to people around the world there are numerous names M45 is known by.  A sample of these is the Pleiades, Seven Sisters, Wolf Pack, Subaru and the Six Nurses.  There many more names and exploring these may be a source of enjoyment for some to track down these names and the cultures that created them.     

M45 is a young open star cluster that formed about 100 million years ago.  Like all open star clusters M45’s component stars are gravitationally bound but this relationship is doomed to end.  Due to tidal forces in open star clusters and outside gravitational influences open star clusters will eventually tear themselves apart.  Open star clusters are the product of star formation so all the individual stars you see in the sky, including the Sun, were at one time in a similar star cluster. 

At a distance of 440 light years this young group of stars shines with an apparent magnitude of 1.6 magnitude putting it well within naked eye visibility.  Due to its bright magnitude it is one of the easiest and most observed deep sky objects.  With the naked eye most will be able to count 5 to 7 individual stars.  Through binoculars and telescopes that number goes up to about 100 stars.  Using advanced observing techniques astronomers have identified about 500 stars with optical light and nearly 1,400 stars using infrared telescopes.  

Due to its proximity to our solar system M45 covers about 115 arc minutes of sky and to see it all in one view low magnifications are required and as such binoculars are well suited for this.  As you observer M45 you will first see the brightest component stars that form a small spoon shape.  This shape causes many to misidentify this star cluster as the Littler Dipper.  Continuing to observe M45 dimmer stars will be seen some of which will form long chains of stars.  

Also of interest are variable and double stars within M45.  To begin to observe and identify these features you will need to locate a map of M45.  One example of a variable star in M45 is the Pleione.  This is a binary star system in which the main component star is of the B spectral class that exhibits additional spectral emissions making it a Be-class star.  The reason for the extra spectral emissions is how fast the main component star rotates.  For a star of its size it rotates near its break up velocity.  The star’s high rotational velocity of one rotation every 11.8 hours causes material to be spun off that forms into a circumstellar disk.  Being close enough to this hot B-class star causes the circumstellar disk to be excited and in turn emit light.  The variability of these stars is linked to the circumstellar disk and when it is excited into emitting light.  Due to these variations Pleione exhibits brightness variations every 35 years identified by spectral class changes.  Variable stars like Pleione are not the best variables to start with but they are worth keeping an eye on over the years.   

Another interesting feature of M45 is a star named HD 23514.  This star is about 9th magnitude and can be seen in large aperture binoculars.  This is a sun like star that displays an interesting signature when observed in infrared.  Using Infrared telescopes HD 23514 is seen to be surrounded by a large amount of hot dust.  Analyzing the heat from the dust particles suggest that they are the product of collisions between materials in a terrestrial planet zone extending through an area of about 2 au from the star.  What astronomers are likely looking at is material orbiting a young star that is in the process of forming into planets.  For more information regarding this interesting star visit http://www.gemini.edu/index.php?q=node/259 

To find M45 you will need to locate the constellation Taurus the Bull. This is easily done by locating Orion the Hunter and following his three belt stars to the northwest.  Doing this you will first find the bright red star Aldebaran which marks the angry eye of Taurus.  Keep following the same path and you will quickly find what first looks like a dim patch of light but when viewed through binoculars will clearly be a spoon shaped group of stars which is M45.  This week’s Messier object is simple to find but will remain a source of enjoyment for all and can offer even the most experienced observer a challenge due to the complexity of the cluster and its components.  For help in tracking down this bright star cluster use the map below.

http://www.iau.org/static/public/constellations/gif/TAU.gif  

Our next Star Party will be held on Friday, February 6, 2015, from dusk until 10 p.m. 

Weather permitting, the St. Louis Astronomical Society and the Science Center will set up a number of telescopes outdoors and be on-hand to answer your questions.  Telescope viewing begins at 7 p.m.  Regardless of the weather on February 6, join us indoors in our planetarium theater for “The Sky Tonight”.  Showtime is at 7 p.m. 

This free, indoor star program will introduce you to the current night sky, the planets, and the seasonal constellations. Doors open 15 minutes before show time. Shows begins at 7 p.m. Sorry, no late admissions due to safety issues in the darkened theater. 

The St. Louis Astronomical Society hosts the monthly Star Parties at the Science Center which are held on the first Friday of each month. Our Monthly Star Parties are open to the public and free of charge.  For more information about the St. Louis Astronomical Society visit their website at www.slasonline.org

Week of Monday, November 17

This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Monday, November 17.  All times are given as local St. Louis time (Central Standard Time).  For definitions of terminology used in the night sky update, click the highlighted text.

Information updated weekly or as needed.

Join us for our next star party, Friday, December 5, 2014 held in association with the St. Louis Astronomical Society. For details, see the information at the bottom of this page.

The Sun and the Moon

Sunrise is at 6:45 a.m. on Monday, November 17 and sunset is at 4:46 p.m. providing us with about 10 hours of daylight.  Even after sunset, the light from the Sun will still dimly illuminate our sky for about 1.5 hours.  This period of time is called twilight, which ends around 6:18 p.m. this week.  For those with a sun dial, solar transit or local noon occurs around 11:46 a.m. this week. 

 

Day

Sunrise

Sunset

10 Nov

6:45 a.m.

4:46 p.m.

11 Nov

6:46 a.m.

4:46 p.m.

12 Nov

6:47 a.m.

4:45 p.m.

13 Nov

6:49 a.m.

4:44 p.m.

14 Nov

6:50 a.m.

4:44 p.m.

15 Nov

6:51 a.m.

4:43 p.m.

16 Nov

6:52 a.m.

4:43 p.m.

         

Moonrise for Monday, November 17 occurs at 1:50 a.m. and moonset will occur at 2:07 p.m.  On Monday, November 17 the Moon will be exhibiting a waning crescent phase with about 22% of the lunar disk illuminated.  New moon occurs on November 22 at 6:33 a.m.  

International Space Station (ISS) Observing

Visible passes of ISS from St. Louis this week occur during the morning hours.  The best of these is on the morning of November 23.  Learn more about this pass and other this week in the table below.

Catch ISS flying over St. Louis in the morning hours starting Monday, November 17. 

Date

Mag

Starts

Max. altitude

Ends

Time

Alt.

Az.

Time

Alt.

Az.

Time

Alt.

Az.

21 Nov

-0.8

05:55:54

10

N

05:57:26

13

NNE

05:58:59

10

NE

23 Nov

-1.2

05:52:45

10

NNW

05:55:19

20

NNE

05:57:52

10

ENE

24 Nov

-0.9

05:05:07

15

NNE

05:05:27

15

NNE

05:07:27

10

ENE

 

Magnitude (Mag): The Measure of brightness for a celestial object.  The lower the value is, the brighter the object will be.

Altitude (Alt):  The angle of a celestial object measured upwards from the observer’s horizon.

Azimuth (Az):  The direction of a celestial object, measured clockwise from an observer’s location with north being 0°, east being 90°, south being 180° and west being 270°. 

For information about ISS flyovers and other visible satellites, visit www.heavens-above.com

Detailed information regarding all unmanned exploration of our universe, missions past, present, and planned, can be found at Jet Propulsion Laboratories:

http://www.jpl.nasa.gov/

The Planets Visible Without A Telescope

Mercury

The most elusive naked eye planet has returned to the morning skies just before sunrise.  It will be difficult to see unless you find a clear eastern horizon free of trees and buildings.  If you have any kind of tree cover east of you Mercury will be too low in the sky.  This will be the best morning apparition of Mercury this year and will get better as the month goes on.

Mars

Mars is now in the constellation Sagittarius and rises before the Sun sets.  Mars will be seen in the southwestern skies about 20 minutes after sunset.  Mars will set by 8:04 p.m. 

Jupiter

The largest planet in the solar system has returned to our evening skies.  Jupiter can be found rising by 11:00 p.m. and will be easily visible by 11:30 p.m. in the eastern sky.  Jupiter can currently be found in the constellation Leo the Lion.    

Uranus and Neptune Opposition 2014

The two most distant planets in our solar system will be at their best for the next couple of months.  Neptune has already reached opposition and Uranus will reach opposition on October 7, 2014.  The opposition of a planet is when it is in opposition with the Sun.  What that means is a planet or other body such as an asteroid is seen on the opposite side of the Earth than the Sun is.  From our perspective this is when an object is at its brightest and also coincides with the object’s closest approach to the Earth.  Only objects further from the Sun than we are can be in opposition. 

Of the two planets Uranus will be the brightest.  Uranus is already appearing as a 5.8 magnitude object and will continue to brighten until October 7.  Uranus is normally a planet that requires binoculars to be seen but when the planet is nearing opposition dark sky observers can see it with the unaided eye.  Through telescopes observers will resolve Uranus into a small disk shaped object that may display a slight greenish blue color.  Large telescopes using high magnifications up to 300x might be able to discern dark and light patches called albedo features.  These features require large aperture telescopes and better than average viewing conditions to be seen. 

Uranus is currently in the constellation Pisces.  Pisces is very difficult to see in light polluted skies so it is better to start with the Great Square of Autumn.  This asterism connects the constellations Andromeda and Pegasus all of which will be seen high in the eastern sky by 10:00 p.m.  As the Great Square sits high in the east if you follow a line connecting the stars Scheat (Beta Peg) through Algenib (Gamma Peg) about the same distance that lays between the two stars you will find three stars the stand next to one another in a straight line.  The brightest of these stars is Delta Piscium.  Uranus is about four degrees south of these stars.  You will need either a desktop planetarium program or detailed star chart to help you pinpoint which star like object is Uranus. 

http://www.iau.org/static/public/constellations/gif/PSC.gif

http://www.iau.org/static/public/constellations/gif/PEG.gif

http://www.skyandtelescope.com/astronomy-news/observing-news/uranus-and-neptune-in-2014/

Neptune reached opposition on August 29, 2014.  It is now at its peak brightness of 7.8 magnitude.  This means that you will need at least binoculars to see this distant planet even when it is at its brightest.  Through binoculars Neptune will appear as a dim star like object in the constellation Aquarius.  To find Neptune first locate the bright star Fomalhaut.  About 6 to 10 degrees north of Fomalhaut you will find six bright stars that are shaped like a hyperboloid.  Scanning the sky further north you will find the star Sigma Aquarii.  Neptune will be just east of this star.      

Using a telescope most will see a star like object that when magnified enough will reveal a greyish blue disk.  Using a large telescope and high magnification up to 300x it may be possible to detect albedo features and Neptune largest moon Triton.  Triton will appear as a dim star right next to Neptune.

Like Uranus Neptune will require some kind of astronomy software of a detailed map to find.  As we pass by these planets in our orbit see if you can detect there shift amongst the background stars.  Below are a few links that will be helpful in locating Neptune and the stars mentioned above.

http://www.iau.org/static/public/constellations/gif/AQR.gif

http://www.skyandtelescope.com/astronomy-news/observing-news/uranus-and-neptune-in-2014/

Constellation of the Month

Each month we will highlight one constellation and some of the objects that can be found within the boundaries of that constellation.  At the start of the month we will list only a few of these objects and each week we will add another to the list.  Some objects will be visible to the unaided eye and some may require a telescope.  Many of the objects listed will require a map of the sky to find or may require repeat observations to notice various properties.  Links to star charts and other information that will be useful in identifying the objects listed will be given at the end of each week’s section. 

This month we will explore the constellation Pegasus.  Pegasus is the famous flying horse that appears in the story of Perseus.  Pegasus was the offspring of Poseidon and Medusa who was born to the world once Medusa was slain in battle by Perseus.  Pegasus is said to have aided Perseus in his fight against the Titan Cetus and also was eventually awarded a place in the stables of Mt. Olympus tasked with caring the lightning bolts of Zeus. 

To find Pegasus first locate the Great Square of Autumn from our list of asterisms we covered last month.  The Great Square connects the constellations Andromeda to Pegasus and will be best seen nearly over head after 10 p.m. 

http://www.iau.org/static/public/constellations/gif/PEG.gif

As for the individual objects we will cover this month Pegasus can be seen as a bit sparse for the beginning observer.  Pegasus has many fine targets to look for however they are a little more on the advanced end of the observing challenges.  All the targets we will talk about this month can be seen in binoculars of varying apertures however they will require the ability to recognize faint and complex star fields to confirm that the object was seen.  Even though I would describe these as advanced observing projects that does not mean the beginning observer cannot find them.  In fact these objects will help push your observing abilities and help refine your observing skills. 

The first object we will cover in November is the globular cluster Messier 15.  This will be the only easy object to find that we cover this month in the night sky update.  Messier 15 is one of the roughly 160 globular clusters found in the Milky Way Galaxy.  Globular clusters are the densely packed ancient star clusters that orbit the outer halo and center of our galaxy.  Messier 15 contains over 100,000 stars that lie at a distance of about 33,000 light years. 

Also of interest is that Messier 15 is one of the prototype globular clusters that exhibit something called core collapse.  The core collapse of a globular cluster is the result of how its stars orbit within the cluster and interact with one another.  Due to a transfer of energy, stars near the core begin to migrate further into the core while the stars associated with the cluster’s halo migrate further out.  The star populations in the core of globular clusters that exhibit core collapse are nearly ten billion times more densely packed than that of the Sun’s neighborhood in the Milky Way.  Visually what that means is the globular cluster will have increasing magnitudes as you look from its edge to its core. 

To find Messier 15 first locate the Great Square of Autumn.  The southwestern most star in the square is called Markab.  From this star if you continue scanning southwest you will find the stars Homan and Theta Pegasi.  From Theta Pegasi look about 7 degrees to the northwest and you will find the star Enif.  Continuing along this same path you will find Messier 15 about 2 to 3 degrees to the northwest of Enif.  It will appear as a fuzzy star.  It is listed at about 6.2 magnitude and will appear to cover about 7 arc minutes of sky.  Due to the core collapse aspect of this globular many of its member stars cover an area of about 21 arc minutes but will remain unseen due to their great distance from us. 

http://www.iau.org/static/public/constellations/gif/PEG.gif 

The object for the week of November 10 is the star 51 Pegasi.  At first glance this is a star that would not seem to warrant a lot of attention.  It is a G-class dwarf star that is similar in size to the Sun (a bit bigger).  It is a main sequence star that is fusing hydrogen at its core; it has a high metallicity and would be considered middle aged for its temperature and mass.  In all 51 Pegasi is very similar to the Sun.  All of these traits that may seem to make 51 Pegasi appear as an average generic star are what makes 51 Pegasi an ideal candidate for a star that has planets.  In 1995 this idea was confirmed when scientists using an observational method called radial velocity discovered a Jupiter size body orbiting the star. 

The potential exoplanet orbiting 51 Pegasi has been formally named 51 Pegasi b with some calling it Bellerophon, who was the ancient Greek hero who slew the Chimera with the assistance of Pegasus.  This was the first exoplanet discovered orbiting a main sequence star.  51 Peg b is a body that orbits 51 Pegasi at a distance of roughly 0.05 AU (4.65 million miles).  It is tidally locked which means the same side of the body is always pointed at the star.  Due to this the side that is pointed at the star would have temperatures reaching 1,800 degrees Fahrenheit. 

There has been some thought that 51 Peg b is a brown dwarf star.  This would suggest that 51 Pegasi is a binary star system.  The reason for this is at the time of 51 Peg b’s discovery a Jupiter sized body forming so close to its parent star seemed highly unlikely.  Since the discovery of 51 Peg b a number of other Jupiter sized planets have been discovered orbiting their stars at similar close distances.  These exoplanets have been called Hot Jupiters.  Most view 51 Peg b as an exoplanet however there is still some debate on the issue.

To find 51 Pegasi first locate the Great Square of Autumn.  Next locate the two stars that make up the western half of the square, Alpha and Beta Pegasi.  About halfway between these two stars there will be two 5th magnitude stars.  The western of these is 51 Pegasi.  The map I will link below shows 51 Pegasi but it does not label it.  So for confirmation you will need to locate a more detailed map of the sky or use planetarium software such as Stellarium.  This software is free to download and is an extremely useful tool for the backyard stargazer. 

http://www.iau.org/static/public/constellations/gif/PEG.gif

The object for the week of November 17 is the supergiant star Enif.  Also known as Epsilon Pegasi this K-class star (orange) is the brightest star in Pegasus.  Enif marks the nose of Pegasus and is one of the guide stars we used to find Messier 15 earlier this month.  Enif is of interest for a number of reasons.  First it is a highly evolved star that is in its supergiant phase.  It is likely beginning to fuse helium into carbon and oxygen and may move on to heavier elements on its way to an explosive death called a supernova.  Enif will likely exist for another few million years before it explodes or becomes a rare oxygen and neon white dwarf star.   

Another reason Enif is of interest is because it is a variable star.  Unlike other variable stars covered in the night sky update, Enif is a variable that does not have a predictable period of variance.  Enif is what has been called a slow LC irregular variable star.  On a few rare occasions Enif has been seen to brighten by about 2 magnitudes for a short period of time (minutes).  These types of variable stars are not well understood due to their variable nature being unpredictable and are very difficult to catch.  It is believed that stars like this have similar flare events as the Sun exhibits only on a much larger scale.  The cause of these enormous flares is not understood and it goes to show that astronomers still have a lot to learn about how stars behave.  If you have an interest in observing this rare variable star it will take dedication and patience and perhaps even a journey into the world of video astronomy.  Video ccd cameras allow an observer to document large periods of time.  Video astronomy also has the benefit of costing far less than a traditional still or FITS ccd camera that many astrophotographers would use.     

To find Enif first locate the Great Square of Autumn.  From the lower right corner of the square look for the bright stars Zeta and Theta Pegasi.  These two stars form the neck of Pegasus and will extend to the southwest in a long straight line.  From Theta Pegasi look to the northwest and you will find Enif.  This star will not be a normal target for many observers however keeping it in mind while you are observing during the fall and winter months may provide you with an exciting opportunity to see a truly rare sight in the sky.  Use the map linked below to help you find Enif and the guide stars listed above. 

http://www.iau.org/static/public/constellations/gif/PEG.gif       

Our next Star Party will be held on Friday, December 5, 2014, from dusk until 10 p.m.

Weather permitting, the St. Louis Astronomical Society and the Science Center will set up a number of telescopes outdoors and be on-hand to answer your questions.  Telescope viewing begins at 8:00 p.m.  Regardless of the weather on December 5, join us indoors in our planetarium theater for “The Sky Tonight”.  Showtime is at 7 p.m.
This free, indoor star program will introduce you to the current night sky, the planets, and the seasonal constellations. Doors open 15 minutes before show time. Shows begins at 7 p.m. Sorry, no late admissions due to safety issues in the darkened theater.

The St. Louis Astronomical Society hosts the monthly Star Parties at the Science Center which are held on the first Friday of each month. Our Monthly Star Parties are open to the public and free of charge.  For more information about the St. Louis Astronomical Society visit their website at www.slasonline.org

Week of Monday, November 10

This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Monday, November 10.  All times are given as local St. Louis time (Central Standard Time).  For definitions of terminology used in the night sky update, click the highlighted text.

Information updated weekly or as needed.

Join us for our next star party, Friday, December 5, 2014 held in association with the St. Louis Astronomical Society. For details, see the information at the bottom of this page.

The Sun and the Moon

Sunrise is at 6:38 a.m. on Monday, November 10 and sunset is at 4:52 p.m. providing us with about 10.5 hours of daylight.  Even after sunset, the light from the Sun will still dimly illuminate our sky for about 1.5 hours.  This period of time is called twilight, which ends around 6:23 p.m. this week.  For those with a sun dial, solar transit or local noon occurs around 11:45 a.m. this week.  

Day

Sunrise

Sunset

10 Nov

6:38 a.m.

4:52 p.m.

11 Nov

6:39 a.m.

4:51 p.m.

12 Nov

6:40 a.m.

4:50 p.m.

13 Nov

6:41 a.m.

4:49 p.m.

14 Nov

6:42 a.m.

4:49 p.m.

15 Nov

6:43 a.m.

4:48 p.m.

16 Nov

6:44 a.m.

4:47 p.m.

        

Moonrise for Monday, November 10 occurs at 8:20 p.m. and moonset will occur at 10:45 a.m. on the following day.  On Monday, November 10 the Moon will be exhibiting a waning gibbous phase with about 84% of the lunar disk illuminated.  Last quarter moon occurs on November 14 at 9:17 a.m.  

International Space Station (ISS) Observing

Visible passes of ISS from St. Louis this week occur during the morning hours.  The best of these is on the morning of November 12. 

Catch ISS flying over St. Louis in the morning hours starting Monday, November 10. 

Date

Mag

Starts

Max. altitude

Ends

Time

Alt.

Az.

Time

Alt.

Az.

Time

Alt.

Az.

11 Nov

-1.3

04:29:21

28

ESE

04:29:21

28

ESE

04:31:49

10

ENE

11 Nov

-2.3

06:02:36

10

W

06:05:32

29

NNW

06:08:29

10

NNE

12 Nov

-3.0

05:15:32

44

WNW

05:15:58

48

NW

05:19:12

10

NE

13 Nov

-0.9

04:28:35

20

NE

04:28:35

20

NE

04:29:46

10

NE

13 Nov

-1.4

06:01:27

10

WNW

06:03:31

16

NNW

06:05:41

10

NNE

14 Nov

-1.6

05:14:19

21

NNW

05:14:19

21

NNW

05:16:28

10

NNE

15 Nov

-0.2

04:27:02

11

NE

04:27:02

11

NE

04:27:08

10

NE

15 Nov

-0.9

06:00:42

10

NNW

06:01:33

11

NNW

06:02:25

10

N

16 Nov

-0.8

05:12:28

13

N

05:12:28

13

N

05:13:22

10

NNE

 

Magnitude (Mag): The Measure of brightness for a celestial object.  The lower the value is, the brighter the object will be.

Altitude (Alt):  The angle of a celestial object measured upwards from the observer’s horizon.

Azimuth (Az):  The direction of a celestial object, measured clockwise from an observer’s location with north being 0°, east being 90°, south being 180° and west being 270°. 

For information about ISS flyovers and other visible satellites, visit www.heavens-above.com

Detailed information regarding all unmanned exploration of our universe, missions past, present, and planned, can be found at Jet Propulsion Laboratories:

http://www.jpl.nasa.gov/

The Planets Visible Without A Telescope

Mars

Mars is now in the constellation Sagittarius and rises before the Sun sets.  Mars will be seen in the southwestern skies about 20 minutes after sunset.  Mars will set by 8:06 p.m. 

Jupiter

The largest planet in the solar system is visible once again in the morning skies.  Jupiter can be found rising by 11:25 p.m. and will be easily visible by 12:00 a.m. in the eastern sky.  Jupiter can currently be found in the constellation Leo the Lion.        

Uranus and Neptune Opposition 2014

The two most distant planets in our solar system will be at their best for the next couple of months.  Neptune has already reached opposition and Uranus will reach opposition on October 7, 2014.  The opposition of a planet is when it is in opposition with the Sun.  What that means is a planet or other body such as an asteroid is seen on the opposite side of the Earth than the Sun is.  From our perspective this is when an object is at its brightest and also coincides with the object’s closest approach to the Earth.  Only objects further from the Sun than we are can be in opposition. 

Of the two planets Uranus will be the brightest.  Uranus is already appearing as a 5.8 magnitude object and will continue to brighten until October 7.  Uranus is normally a planet that requires binoculars to be seen but when the planet is nearing opposition dark sky observers can see it with the unaided eye.  Through telescopes observers will resolve Uranus into a small disk shaped object that may display a slight greenish blue color.  Large telescopes using high magnifications up to 300x might be able to discern dark and light patches called albedo features.  These features require large aperture telescopes and better than average viewing conditions to be seen. 

Uranus is currently in the constellation Pisces.  Pisces is very difficult to see in light polluted skies so it is better to start with the Great Square of Autumn.  This asterism connects the constellations Andromeda and Pegasus all of which will be seen high in the eastern sky by 10:00 p.m.  As the Great Square sits high in the east if you follow a line connecting the stars Scheat (Beta Peg) through Algenib (Gamma Peg) about the same distance that lays between the two stars you will find three stars the stand next to one another in a straight line.  The brightest of these stars is Delta Piscium.  Uranus is about four degrees south of these stars.  You will need either a desktop planetarium program or detailed star chart to help you pinpoint which star like object is Uranus. 

http://www.iau.org/static/public/constellations/gif/PSC.gif

http://www.iau.org/static/public/constellations/gif/PEG.gif

http://www.skyandtelescope.com/astronomy-news/observing-news/uranus-and-neptune-in-2014/

Neptune reached opposition on August 29, 2014.  It is now at its peak brightness of 7.8 magnitude.  This means that you will need at least binoculars to see this distant planet even when it is at its brightest.  Through binoculars Neptune will appear as a dim star like object in the constellation Aquarius.  To find Neptune first locate the bright star Fomalhaut.  About 6 to 10 degrees north of Fomalhaut you will find six bright stars that are shaped like a hyperboloid.  Scanning the sky further north you will find the star Sigma Aquarii.  Neptune will be just east of this star.      

Using a telescope most will see a star like object that when magnified enough will reveal a greyish blue disk.  Using a large telescope and high magnification up to 300x it may be possible to detect albedo features and Neptune largest moon Triton.  Triton will appear as a dim star right next to Neptune.

Like Uranus Neptune will require some kind of astronomy software of a detailed map to find.  As we pass by these planets in our orbit see if you can detect there shift amongst the background stars.  Below are a few links that will be helpful in locating Neptune and the stars mentioned above.

http://www.iau.org/static/public/constellations/gif/AQR.gif

http://www.skyandtelescope.com/astronomy-news/observing-news/uranus-and-neptune-in-2014/

Constellation of the Month

Each month we will highlight one constellation and some of the objects that can be found within the boundaries of that constellation.  At the start of the month we will list only a few of these objects and each week we will add another to the list.  Some objects will be visible to the unaided eye and some may require a telescope.  Many of the objects listed will require a map of the sky to find or may require repeat observations to notice various properties.  Links to star charts and other information that will be useful in identifying the objects listed will be given at the end of each week’s section. 

This month we will explore the constellation Pegasus.  Pegasus is the famous flying horse that appears in the story of Perseus.  Pegasus was the offspring of Poseidon and Medusa who was born to the world once Medusa was slain in battle by Perseus.  Pegasus is said to have aided Perseus in his fight against the Titan Cetus and also was eventually awarded a place in the stables of Mt. Olympus tasked with caring the lightning bolts of Zeus. 

To find Pegasus first locate the Great Square of Autumn from our list of asterisms we covered last month.  The Great Square connects the constellations Andromeda to Pegasus and will be best seen nearly over head after 10 p.m. 

http://www.iau.org/static/public/constellations/gif/PEG.gif

As for the individual objects we will cover this month Pegasus can be seen as a bit sparse for the beginning observer.  Pegasus has many fine targets to look for however they are a little more on the advanced end of the observing challenges.  All the targets we will talk about this month can be seen in binoculars of varying apertures however they will require the ability to recognize faint and complex star fields to confirm that the object was seen.  Even though I would describe these as advanced observing projects that does not mean the beginning observer cannot find them.  In fact these objects will help push your observing abilities and help refine your observing skills. 

The first object we will cover in November is the globular cluster Messier 15.  This will be the only easy object to find that we cover this month in the night sky update.  Messier 15 is one of the roughly 160 globular clusters found in the Milky Way Galaxy.  Globular clusters are the densely packed ancient star clusters that orbit the outer halo and center of our galaxy.  Messier 15 contains over 100,000 stars that lie at a distance of about 33,000 light years. 

Also of interest is that Messier 15 is one of the prototype globular clusters that exhibit something called core collapse.  The core collapse of a globular cluster is the result of how its stars orbit within the cluster and interact with one another.  Due to a transfer of energy, stars near the core begin to migrate further into the core while the stars associated with the cluster’s halo migrate further out.  The star populations in the core of globular clusters that exhibit core collapse are nearly ten billion times more densely packed than that of the Sun’s neighborhood in the Milky Way.  Visually what that means is the globular cluster will have increasing magnitudes as you look from its edge to its core. 

To find Messier 15 first locate the Great Square of Autumn.  The southwestern most star in the square is called Markab.  From this star if you continue scanning southwest you will find the stars Homan and Theta Pegasi.  From Theta Pegasi look about 7 degrees to the northwest and you will find the star Enif.  Continuing along this same path you will find Messier 15 about 2 to 3 degrees to the northwest of Enif.  It will appear as a fuzzy star.  It is listed at about 6.2 magnitude and will appear to cover about 7 arc minutes of sky.  Due to the core collapse aspect of this globular many of its member stars cover an area of about 21 arc minutes but will remain unseen due to their great distance from us. 

http://www.iau.org/static/public/constellations/gif/PEG.gif 

The object for the week of November 10 is the star 51 Pegasi.  At first glance this is a star that would not seem to warrant a lot of attention.  It is a G-class dwarf star that is similar in size to the Sun (a bit bigger).  It is a main sequence star that is fusing hydrogen at its core; it has a high metallicity and would be considered middle aged for its temperature and mass.  In all 51 Pegasi is very similar to the Sun.  All of these traits that may seem to make 51 Pegasi appear as an average generic star are what makes 51 Pegasi an ideal candidate for a star that has planets.  In 1995 this idea was confirmed when scientists using an observational method called radial velocity discovered a Jupiter size body orbiting the star. 

The potential exoplanet orbiting 51 Pegasi has been formally named 51 Pegasi b with some calling it Bellerophon, who was the ancient Greek hero who slew the Chimera with the assistance of Pegasus.  This was the first exoplanet discovered orbiting a main sequence star.  51 Peg b is a body that orbits 51 Pegasi at a distance of roughly 0.05 AU (4.65 million miles).  It is tidally locked which means the same side of the body is always pointed at the star.  Due to this the side that is pointed at the star would have temperatures reaching 1,800 degrees Fahrenheit. 

There has been some thought that 51 Peg b is a brown dwarf star.  This would suggest that 51 Pegasi is a binary star system.  The reason for this is at the time of 51 Peg b’s discovery a Jupiter sized body forming so close to its parent star seemed highly unlikely.  Since the discovery of 51 Peg b a number of other Jupiter sized planets have been discovered orbiting their stars at similar close distances.  These exoplanets have been called Hot Jupiters.  Most view 51 Peg b as an exoplanet however there is still some debate on the issue.

To find 51 Pegasi first locate the Great Square of Autumn.  Next locate the two stars that make up the western half of the square, Alpha and Beta Pegasi.  About halfway between these two stars there will be two 5th magnitude stars.  The western of these is 51 Pegasi.  The map I will link below shows 51 Pegasi but it does not label it.  So for confirmation you will need to locate a more detailed map of the sky or use planetarium software such as Stellarium.  This software is free to download and is an extremely useful tool for the backyard stargazer. 

http://www.iau.org/static/public/constellations/gif/PEG.gif            

Our next Star Party will be held on Friday, December 5, 2014, from dusk until 10 p.m.

Weather permitting, the St. Louis Astronomical Society and the Science Center will set up a number of telescopes outdoors and be on-hand to answer your questions.  Telescope viewing begins at 8:00 p.m.  Regardless of the weather on December 5, join us indoors in our planetarium theater for “The Sky Tonight”.  Showtime is at 7 p.m.
This free, indoor star program will introduce you to the current night sky, the planets, and the seasonal constellations. Doors open 15 minutes before show time. Shows begins at 7 p.m. Sorry, no late admissions due to safety issues in the darkened theater.

The St. Louis Astronomical Society hosts the monthly Star Parties at the Science Center which are held on the first Friday of each month. Our Monthly Star Parties are open to the public and free of charge.  For more information about the St. Louis Astronomical Society visit their website at www.slasonline.org

Week of November 3, 2014

This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Monday, November 3.  All times are given as local St. Louis time (Central Standard Time).  For definitions of terminology used in the night sky update, click the highlighted text.

Information updated weekly or as needed.

 Join us for our next star party, Friday, November 7, 2014 held in association with the St. Louis Astronomical Society. For details, see the information at the bottom of this page.

The Sun and the Moon

Sunrise is at 6:30 a.m. on Monday, November 3 and sunset is at 4:59 p.m. providing us with about 10.5 hours of daylight.  Even after sunset, the light from the Sun will still dimly illuminate our sky for about 1.5 hours.  This period of time is called twilight, which ends around 6:26 p.m. this week.  For those with a sun dial, solar transit or local noon occurs around 11:45 p.m. this week. 

Day

Sunrise

Sunset

03 Nov

6:30 a.m.

4:59 p.m.

04 Nov

6:31 a.m.

4:58 p.m.

05 Nov

6:32 a.m.

4:57 p.m.

06 Nov

6:33 a.m.

4:56 p.m.

07 Nov

6:34 a.m.

4:55 p.m.

08 Nov

6:35 a.m.

4:54 p.m.

09 Nov

6:37 a.m.

4:53 p.m.

Moonrise for Monday, November 3 occurs at 3:05 p.m. and moonset will occur at 3:51 a.m. on the following day.  On Monday, November 3 the Moon will be exhibiting a waxing gibbous phase with about 87% of the lunar disk illuminated.  Full moon occurs on November 6 at 4:23 p.m.  November’s full moon is known as the Full Beaver Moon.

International Space Station (ISS) Observing

Visible passes of ISS from St. Louis this week occur during the morning hours.  The best of these is on the mornings of November 9 and 10. 

Catch ISS flying over St. Louis in the morning hours starting Monday, November 3. 

Date

Mag

Starts

Max. altitude

Ends

Time

Alt.

Az.

Time

Alt.

Az.

Time

Alt.

Az.

07 Nov

-1.5

06:06:44

10

SSW

06:09:47

35

SE

06:12:51

10

ENE

08 Nov

-0.5

05:18:09

10

S

05:20:35

19

SE

05:23:02

10

E

09 Nov

-3.3

06:04:22

10

SW

06:07:40

74

NW

06:10:59

10

NE

10 Nov

-2.7

05:15:49

16

SW

05:18:18

58

SE

05:21:34

10

ENE

Magnitude (Mag): The Measure of brightness for a celestial object.  The lower the value is, the brighter the object will be.

Altitude (Alt):  The angle of a celestial object measured upwards from the observer’s horizon.

Azimuth (Az):  The direction of a celestial object, measured clockwise from an observer’s location with north being 0°, east being 90°, south being 180° and west being 270°.

For information about ISS flyovers and other visible satellites, visit www.heavens-above.com

Detailed information regarding all unmanned exploration of our universe, missions past, present, and planned, can be found at Jet Propulsion Laboratories:

http://www.jpl.nasa.gov/

The Planets Visible Without A Telescope

Mars

Mars is now in the constellation Sagittarius and rises before the Sun sets.  Mars will be seen in the southwestern skies about 20 minutes after sunset.  Mars will set by 8:09 p.m. 

Jupiter

The largest planet in the solar system is visible once again in the morning skies.  Jupiter can be found rising by 11:49 a.m. and will be easily visible by 12:30 a.m. in the eastern sky.  Jupiter can currently be found in the constellation Leo the Lion.    

Uranus and Neptune Opposition 2014

The two most distant planets in our solar system will be at their best for the next couple of months.  Neptune has already reached opposition and Uranus will reach opposition on October 7, 2014.  The opposition of a planet is when it is in opposition with the Sun.  What that means is a planet or other body such as an asteroid is seen on the opposite side of the Earth than the Sun is.  From our perspective this is when an object is at its brightest and also coincides with the object’s closest approach to the Earth.  Only objects further from the Sun than we are can be in opposition. 

Of the two planets Uranus will be the brightest.  Uranus is already appearing as a 5.8 magnitude object and will continue to brighten until October 7.  Uranus is normally a planet that requires binoculars to be seen but when the planet is nearing opposition dark sky observers can see it with the unaided eye.  Through telescopes observers will resolve Uranus into a small disk shaped object that may display a slight greenish blue color.  Large telescopes using high magnifications up to 300x might be able to discern dark and light patches called albedo features.  These features require large aperture telescopes and better than average viewing conditions to be seen. 

Uranus is currently in the constellation Pisces.  Pisces is very difficult to see in light polluted skies so it is better to start with the Great Square of Autumn.  This asterism connects the constellations Andromeda and Pegasus all of which will be seen high in the eastern sky by 10:00 p.m.  As the Great Square sits high in the east if you follow a line connecting the stars Scheat (Beta Peg) through Algenib (Gamma Peg) about the same distance that lays between the two stars you will find three stars the stand next to one another in a straight line.  The brightest of these stars is Delta Piscium.  Uranus is about four degrees south of these stars.  You will need either a desktop planetarium program or detailed star chart to help you pinpoint which star like object is Uranus. 

http://www.iau.org/static/public/constellations/gif/PSC.gif

http://www.iau.org/static/public/constellations/gif/PEG.gif

http://www.skyandtelescope.com/astronomy-news/observing-news/uranus-and-neptune-in-2014/

Neptune reached opposition on August 29, 2014.  It is now at its peak brightness of 7.8 magnitude.  This means that you will need at least binoculars to see this distant planet even when it is at its brightest.  Through binoculars Neptune will appear as a dim star like object in the constellation Aquarius.  To find Neptune first locate the bright star Fomalhaut.  About 6 to 10 degrees north of Fomalhaut you will find six bright stars that are shaped like a hyperboloid.  Scanning the sky further north you will find the star Sigma Aquarii.  Neptune will be just east of this star.       

Using a telescope most will see a star like object that when magnified enough will reveal a greyish blue disk.  Using a large telescope and high magnification up to 300x it may be possible to detect albedo features and Neptune largest moon Triton.  Triton will appear as a dim star right next to Neptune.

Like Uranus Neptune will require some kind of astronomy software of a detailed map to find.  As we pass by these planets in our orbit see if you can detect there shift amongst the background stars.  Below are a few links that will be helpful in locating Neptune and the stars mentioned above.

http://www.iau.org/static/public/constellations/gif/AQR.gif

http://www.skyandtelescope.com/astronomy-news/observing-news/uranus-and-neptune-in-2014/

Constellation of the Month

Each month we will highlight one constellation and some of the objects that can be found within the boundaries of that constellation.  At the start of the month we will list only a few of these objects and each week we will add another to the list.  Some objects will be visible to the unaided eye and some may require a telescope.  Many of the objects listed will require a map of the sky to find or may require repeat observations to notice various properties.  Links to star charts and other information that will be useful in identifying the objects listed will be given at the end of each week’s section. 

This month we will explore the constellation Pegasus.  Pegasus is the famous flying horse that appears in the story of Perseus.  Pegasus was the offspring of Poseidon and Medusa who was born to the world once Medusa was slain in battle by Perseus.  Pegasus is said to have aided Perseus in his fight against the Titan Cetus and also was eventually awarded a place in the stables of Mt. Olympus tasked with caring the lightning bolts of Zeus. 

To find Pegasus first locate the Great Square of Autumn from our list of asterisms we covered last month.  The Great Square connects the constellations Andromeda to Pegasus and will be best seen nearly over head after 10 p.m. 

http://www.iau.org/static/public/constellations/gif/PEG.gif

As for the individual objects we will cover this month Pegasus can be seen as a bit sparse for the beginning observer.  Pegasus has many fine targets to look for however they are a little more on the advanced end of the observing challenges.  All the targets we will talk about this month can be seen in binoculars of varying apertures however they will require the ability to recognize faint and complex star fields to confirm that the object was seen.  Even though I would describe these as advanced observing projects that does not mean the beginning observer cannot find them.  In fact these objects will help push your observing abilities and help refine your observing skills. 

The first object we will cover in November is the globular cluster Messier 15.  This will be the only easy object to find that we cover this month in the night sky update.  Messier 15 is one of the roughly 160 globular clusters found in the Milky Way Galaxy.  Globular clusters are the densely packed ancient star clusters that orbit the outer halo and center of our galaxy.  Messier 15 contains over 100,000 stars that lie at a distance of about 33,000 light years. 

Also of interest is that Messier 15 is one of the prototype globular clusters that exhibit something called core collapse.  The core collapse of a globular cluster is the result of how its stars orbit within the cluster and interact with one another.  Due to a transfer of energy, stars near the core begin to migrate further into the core while the stars associated with the cluster’s halo migrate further out.  The star populations in the core of globular clusters that exhibit core collapse are nearly ten billion times more densely packed than that of the Sun’s neighborhood in the Milky Way.  Visually what that means is the globular cluster will have increasing magnitudes as you look from its edge to its core. 

To find Messier 15 first locate the Great Square of Autumn.  The southwestern most star in the square is called Markab.  From this star if you continue scanning southwest you will find the stars Homan and Theta Pegasi.  From Theta Pegasi look about 7 degrees to the northwest and you will find the star Enif.  Continuing along this same path you will find Messier 15 about 2 to 3 degrees to the northwest of Enif.  It will appear as a fuzzy star.  It is listed at about 6.2 magnitude and will appear to cover about 7 arc minutes of sky.  Due to the core collapse aspect of this globular many of its member stars cover an area of about 21 arc minutes but will remain unseen due to their great distance from us. 

http://www.iau.org/static/public/constellations/gif/PEG.gif

Our next Star Party will be held on Friday, November 7, 2014, from dusk until 10 p.m.

Weather permitting, the St. Louis Astronomical Society and the Science Center will set up a number of telescopes outdoors and be on-hand to answer your questions.  Telescope viewing begins at 8:00 p.m.  Regardless of the weather on November 7, join us indoors in our planetarium theater for “The Sky Tonight”.  Showtime is at 7 p.m.

This free, indoor star program will introduce you to the current night sky, the planets, and the seasonal constellations. Doors open 15 minutes before show time. Shows begins at 7 p.m. Sorry, no late admissions due to safety issues in the darkened theater.

The St. Louis Astronomical Society hosts the monthly Star Parties at the Science Center which are held on the first Friday of each month. Our Monthly Star Parties are open to the public and free of charge.  For more information about the St. Louis Astronomical Society visit their website at www.slasonline.org

 

 

 

 

Week of Monday, October 27

This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Monday, October 27.  All times are given as local St. Louis time (Central Daylight Time).  For definitions of terminology used in the night sky update, click the highlighted text.

Information updated weekly or as needed.

Join us for our next star party, Friday, November 7, 2014 held in association with the St. Louis Astronomical Society. For details, see the information at the bottom of this page.

The Sun and the Moon

Sunrise is at 7:22 a.m. on Monday, October 27 and sunset is at 6:07 p.m. providing us with about 10.75 hours of daylight.  Even after sunset, the light from the Sun will still dimly illuminate our sky for about 1.5 hours.  This period of time is called twilight, which ends around 7:36 p.m. this week.  For those with a sun dial, solar transit or local noon occurs around 12:45 p.m. this week. 

Daylight savings time ends on November 2.  Remember to fall back one hour once we return to Central Standard Time on November 2, 2014.  Below you will find sunrise and sunset times for the rest of the week.  Note that all times in this table except for November 2 are in Central Daylight Time.   

Day

Sunrise

Sunset

27 Oct

7:22 a.m.

6:07 p.m.

28 Oct

7:24 a.m.

6:06 p.m.

29 Oct

7:25 a.m.

6:04 p.m.

30 Oct

7:26 a.m.

6:03 p.m.

31 Oct

7:27 a.m.

6:02 p.m.

01 Nov

7:28 a.m.

6:01 p.m.

02 Nov

6:29 a.m.

5:00 p.m.

        

Moonrise for Monday, October 27 occurs at 10:57 a.m. and moonset will occur at 9:14 p.m.  On Monday, October 27 the Moon will be exhibiting a waxing crescent phase with about 15% of the lunar disk illuminated.  First quarter moon occurs on October 30 at 9:48 p.m.

International Space Station (ISS) Observing

Visible passes of ISS from St. Louis this week occur during the evening hours.  The best of these is on the evening of October 28. 

Catch ISS flying over St. Louis in the evening hours starting Monday, October 27. 

Date

Mag

Starts

Max. altitude

Ends

Time

Alt.

Az.

Time

Alt.

Az.

Time

Alt.

Az.

27 Oct

-1.5

19:24:08

10

WNW

19:27:08

31

SW

19:30:06

10

SSE

28 Oct

-2.7

18:34:38

10

WNW

18:37:56

60

SW

18:41:13

10

SE

29 Oct

 0.1

19:24:00

10

WSW

19:24:52

11

SW

19:25:44

10

SW

30 Oct

-0.3

18:33:12

10

W

18:35:43

20

SW

18:38:13

10

S

 

Magnitude (Mag): The Measure of brightness for a celestial object.  The lower the value is, the brighter the object will be.

Altitude (Alt):  The angle of a celestial object measured upwards from the observer’s horizon.

Azimuth (Az):  The direction of a celestial object, measured clockwise from an observer’s location with north being 0°, east being 90°, south being 180° and west being 270°. 

For information about ISS flyovers and other visible satellites, visit www.heavens-above.com

Detailed information regarding all unmanned exploration of our universe, missions past, present, and planned, can be found at Jet Propulsion Laboratories:

http://www.jpl.nasa.gov/

The Planets Visible Without A Telescope

Mars

Mars is now in the constellation Ophiuchus and rises before the Sun sets.  Mars will be seen in the southwestern skies about 20 minutes after sunset.  Mars will set by 9:13 p.m. 

Jupiter

The largest planet in the solar system is visible once again in the morning skies.  Jupiter can be found rising by 1:16 a.m. and will be easily visible by 1:40 a.m.        

Uranus and Neptune Opposition 2014

The two most distant planets in our solar system will be at their best for the next couple of months.  Neptune has already reached opposition and Uranus will reach opposition on October 7, 2014.  The opposition of a planet is when it is in opposition with the Sun.  What that means is a planet or other body such as an asteroid is seen on the opposite side of the Earth than the Sun is.  From our perspective this is when an object is at its brightest and also coincides with the object’s closest approach to the Earth.  Only objects further from the Sun than we are can be in opposition. 

Of the two planets Uranus will be the brightest.  Uranus is already appearing as a 5.8 magnitude object and will continue to brighten until October 7.  Uranus is normally a planet that requires binoculars to be seen but when the planet is nearing opposition dark sky observers can see it with the unaided eye.  Through telescopes observers will resolve Uranus into a small disk shaped object that may display a slight greenish blue color.  Large telescopes using high magnifications up to 300x might be able to discern dark and light patches called albedo features.  These features require large aperture telescopes and better than average viewing conditions to be seen. 

Uranus is currently in the constellation Pisces.  Pisces is very difficult to see in light polluted skies so it is better to start with the Great Square of Autumn.  This asterism connects the constellations Andromeda and Pegasus all of which will be seen high in the eastern sky by 10:00 p.m.  As the Great Square sits high in the east if you follow a line connecting the stars Scheat (Beta Peg) through Algenib (Gamma Peg) about the same distance that lays between the two stars you will find three stars the stand next to one another in a straight line.  The brightest of these stars is Delta Piscium.  Uranus is about four degrees south of these stars.  You will need either a desktop planetarium program or detailed star chart to help you pinpoint which star like object is Uranus. 

http://www.iau.org/static/public/constellations/gif/PSC.gif

http://www.iau.org/static/public/constellations/gif/PEG.gif

http://www.skyandtelescope.com/astronomy-news/observing-news/uranus-and-neptune-in-2014/

Neptune reached opposition on August 29, 2014.  It is now at its peak brightness of 7.8 magnitude.  This means that you will need at least binoculars to see this distant planet even when it is at its brightest.  Through binoculars Neptune will appear as a dim star like object in the constellation Aquarius.  To find Neptune first locate the bright star Fomalhaut.  About 6 to 10 degrees north of Fomalhaut you will find six bright stars that are shaped like a hyperboloid.  Scanning the sky further north you will find the star Sigma Aquarii.  Neptune will be just east of this star.      

Using a telescope most will see a star like object that when magnified enough will reveal a greyish blue disk.  Using a large telescope and high magnification up to 300x it may be possible to detect albedo features and Neptune largest moon Triton.  Triton will appear as a dim star right next to Neptune.

Like Uranus Neptune will require some kind of astronomy software of a detailed map to find.  As we pass by these planets in our orbit see if you can detect there shift amongst the background stars.  Below are a few links that will be helpful in locating Neptune and the stars mentioned above.

http://www.iau.org/static/public/constellations/gif/AQR.gif

http://www.skyandtelescope.com/astronomy-news/observing-news/uranus-and-neptune-in-2014/

Constellation of the Month

Each month we will highlight one constellation and some of the objects that can be found within the boundaries of that constellation.  At the start of the month we will list only a few of these objects and each week we will add another to the list.  Some objects will be visible to the unaided eye and some may require a telescope.  Many of the objects listed will require a map of the sky to find or may require repeat observations to notice various properties.  Links to star charts and other information that will be useful in identifying the objects listed will be given at the end of each week’s section. 

This month we will once again forego a single constellation and discuss a number of different patterns.  This month we will work on finding some of the informal groupings of stars called asterisms.  These informal patterns can be large groups that contain multiple constellations or they can be small dim groupings that require a telescope to see. Many of them serve as useful markers in the sky that help you find dimmer and more difficult objects.  

The first asterism we will cover in October is the Summer Triangle.  This is one we have mentioned and used numerous times in the night sky update.  Last week in fact we used it in reference to finding Cygnus the Swan.  Other constellations that comprise this asterism are Lyra the Harp and Aquila the Eagle.  Inside the Summer Triangle we find the constellations Vulpecula the Fox, Sagitta the Arrow and just outside the eastern edge is Delphinus the Dolphin.  Scattered throughout these constellations are many gems for double star observers, numerous open star clusters and a number of nebulas.  The first step in finding all of these is taken by first locating the Summer Triangle.

Also of interest regarding the Summer Triangle is a Mission called Kepler.  This is a space telescope that steadily observed the patch of sky between Cygnus and Lyra.  What Kepler was looking for was the subtle changes in a star’s light due to the effects of a planet orbiting around it.  Thanks to the Kepler mission and other research programs scientists currently have 5,022 candidate exoplanets (planets orbiting other stars) of which 1,746 have been confirmed.  With these numbers scientists have estimated that there are likely as many planets as there are stars in the Milky Way galaxy if not more.  If you would like to learn more about Kepler and the hunt for exoplanets visit http://planetquest.jpl.nasa.gov/   

With a name like the Summer Triangle you would think that we would start losing this asterism soon as we approach winter.  Due to the longer nights we will continue to see the Summer Triangle for the rest of the year.  Tonight go outside and simply look straight up and you should see the three bright stars Deneb, Vega and Altair that define the triangle shape.  Once you can find this asterism grab some binocular and a reclined chair and just start scanning this part of the sky.  Dense star fields and numerous stars clusters will keep you busy for some time. 

The asterism we will cover for the week of October 6 is the Great Square of Autumn.  This is another asterism that can serve as a reference point or guide post in the sky.  Much like the Summer Triangle, the Great Square of Autumn can be used to find a number of constellations and other objects of interest.  The Great Square primarily consists of two constellations; Andromeda and Pegasus.  As most of the square is in Pegasus it is also called the Square of Pegasus.  The Great Square of Autumn can also help you find the constellations Piscis, Cetus, Aquarius, Lacerta and Equuleus. 

One of the more challenging objects the Great Square can help you find is the bright variable star Mira.  Mira is a long period variable that every 333 days or so will brighten from 10th magnitude up to about 3rd magnitude.  This change does not occur in one day but over the entire 333 day cycle.  The brightening of the Mira takes about 100 days and will take twice as long to fade back to minima.  Mira was one of the first variable stars other than bright supernovas or novae to be discovered and it certainly is one of the brightest.  Unfortunately Mira has already peaked in brightness and is already well into its slow downward fade for 2014. 

Mira is an M-class red giant star that is approximately 6 billion years old.  The variable nature of Mira is due to an internal pulsation which is a result of the unstable nature of the star.  The Sun will likely come to a similar state as it evolves into a red giant star in another 5 billion years.  Mira is one of the brightest stars in the constellation Cetus.  Depending on the map you use to find Mira you may find it labeled Omicron Ceti.  

http://www.iau.org/static/public/constellations/gif/CET.gif

Finding the Great Square of Autumn is simple but it does depend on what time you look for it.  After sunset the square will be seen low in the east looking more like a diamond.  At midnight it will be nearly overhead and before sunrise it will be found low in the west. 

For the rest of the month we will cover asterisms that are still helpful guides in the sky but they will be found in individual constellations and will require an optical device such as binoculars to see.

The asterism for the week of October 13 is the star cluster known as the ET cluster.  This group of roughly 100-150 stars is frequently called the ET Cluster but officially it is named NGC 457.  The name ET Cluster is comes from the idea that the stars of NGC 457 look a bit like the famous alien character from the movie E.T.  The human brain is well suited to finding familiar patterns in a seemingly random grouping of objects.  Much like people do with clouds or blots of paint people see all kinds of patterns in the stars which of course is the theme of this month’s night sky update.  Other names given to NGC 457 are Caldwell 13 (catalog number), the Owl Cluster and the Number 5 is Alive Cluster.

The ET Cluster is located in the constellation Cassiopeia near the bright star Delta Cassiopeiae.  This 21 million year old cluster of stars is situated about 10 thousand light years away in the Perseus Arm of the Milky Way Galaxy.  When you look at it through binoculars you will see a dim patch of light with about 20 or 30 stars visible.  With telescopes you can see around 100 stars that at even such a great distance will seem detached from the background stars.  Once you are looking at the ET Cluster you will notice two bright stars called Psi-1 and Psi-2 Cassiopeiae.  These two stars represent the eyes of ET which may not be in the cluster itself.  Below the eyes there is a long chain of stars that represents ET’s arms and below that is the main body of the cluster which is seen as ET’s body. 

To find the ET cluster first find the W-shape of the constellation Cassiopeia.  The bright “W” asterism of Cassiopeia will be visible high in the northeast after sunset.  As the night progresses the “W” will pass overhead in the north and will be seen in the northwest before sunrise.  Once you can identify Cassiopeia locate the two western most stars of the W-shape called Epsilon and Delta Cassiopeiae.  Then follow a line from Epsilon to Delta and continue for another 2.5 degrees below Delta and you will find the ET Cluster.   

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Any way you look at the ET cluster it stands out as one of the best in Cassiopeia and it sits in a crowed part of the sky in regards to other open star clusters.  If you can find the ET Cluster there are a number of open clusters within a 5 degree distance to the north.  A few of them are M103, NGC 663, NGC 654, NGC 659, NGC 436 and NGC 381.  From a dark location most of these are excellent binocular targets.        

The asterism for the week of October 20 is Kemble’s Cascade.  This is currently my favorite asterism and is one that we covered in April when talking about the constellation Camelopardalis.  I choose to return to this object for a few reasons.  First it is beautiful, second it is one of those objects that favor binoculars over telescopes and third the part of the sky it is in is loaded with lots of great objects in other constellations.  It is because of this last reason that part of the fun in observing Kemble’s cascade is in the search for it. 

This grouping of stars was discovered by an amateur astronomer named Lucian Kemble.  He was scanning Camelopardalis and noticed a string of stars that spanned about 2.5 degrees of sky.  It was later named in his honor and remains a popular target in the sparse constellation of Camelopardalis.

Kemble’s Cascade is a string of 20 stars, mostly 7th to 10th magnitude, which spans about 2.5 degrees.  The center of the string is accented with a 5th magnitude star.  The stars that make up Kemble’s Cascade are not related to each so what we see is just a chance alignment.  Following this cascade of stars to the southwest will bring us to an open star cluster called NGC 1502.  This cluster contains about 45 stars that will appear as a faint glow at the end of Kemble’s Cascade. 

One way to find Kemble’s Cascade is by first locating Beta and Alpha Cam using binoculars.  This can be done by first following the steps to find last week’s ET cluster.  The two bright stars in Cassiopeia, Delta and Epsilon Cassiopeiae will also help you find Kemble’s cascade. 

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Scan from Delta to Epsilon Cassiopeiae about 10 degrees to the northwest.  This will bring you to Gamma Cam.  Below Gamma Cam you will find Alpha and Beta Cam

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From Alpha Cam scan about 5 degrees to the east and you will find Kemble’s Cascade.

My favorite way to find Kemble’s Cascade is to first find the constellation Perseus south of the western half of the constellation Cassiopeia.

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With binoculars locate the bright star Mirfak at the center of Perseus.  This bright star is in the middle of the Alpha Persei Moving group of stars.  It is a nearby broad open star cluster that is beautiful in low power binoculars.  From here move north the helmet of Perseus to find NGC 869/884 also known as the Perseus Double Cluster.  Two degrees to the north you can find Stock 2 also known as the muscle man cluster.  A bit north and west from Stock 2 is the Heart and Soul nebulas and a scattering of dimmer open star clusters.  The Heart and Souls Nebulas are two beautiful emission nebulae that will require dark skies to be seen.  And finally another five degrees to the west you will find Kemble’s Cascade.  Now I admit that this method of finding Kemble’s Cascade seems a bit complicated and will require a more advanced map to identify all the objects just named, but it is not often you can star hop using deep sky objects instead stars.     

If you are up for a challenge and have dark skies there are even a few dim galaxies you can try to find that are north and west of Kemble’s Cascade called IC 342 and IC 356.  Unfortunately for these you will need large binoculars or a telescope to seem them. 

The final asterism we will cover is called the Coat Hanger asterism.  This group of stars was once believed to be a star cluster and was named Collinder 399.  After results from the Hipparcos satellite were analyzed it became clear that this grouping of stars was just a chance alignment.  It consists of ten stars with six in a line and four forming the hook of the hanger.  The member stars have distances ranging from 200 to a bit over 1000 light years. 

To find the Coat Hanger asterism we have to return the first asterism covered this month, the Summer Triangle.  The Coat Hanger is located near the eastern edge of the minor constellation Vulpecula the Fox.  Unfortunately Vulpecula is not the brightest of constellations so we will use the bright Summer Triangle stars Altair and Vega to locate the Coat Hanger.  Using binoculars scan between the bright stars Altair and Vega.  About 1/3 the distance between them is where you will find the Coat Hanger.  The Coat Hanger will appear upside down.

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Due to the amount of sky covered by the asterism binoculars may be the preferred way to see the Coat Hanger.  If you chose a telescope make sure to use low power eyepieces when observing this pattern of stars.  Other Objects in the vicinity of this asterism are the planetary nebulae M27 and M57, M11 the Wild Duck Cluster and the globular cluster M71.    

Our next Star Party will be held on Friday, November 7, 2014, from dusk until 10 p.m.

Weather permitting, the St. Louis Astronomical Society and the Science Center will set up a number of telescopes outdoors and be on-hand to answer your questions.  Telescope viewing begins at 8:00 p.m.  Regardless of the weather on November 7, join us indoors in our planetarium theater for “The Sky Tonight”.  Showtime is at 7 p.m.
This free, indoor star program will introduce you to the current night sky, the planets, and the seasonal constellations. Doors open 15 minutes before show time. Shows begins at 7 p.m. Sorry, no late admissions due to safety issues in the darkened theater.

The St. Louis Astronomical Society hosts the monthly Star Parties at the Science Center which are held on the first Friday of each month. Our Monthly Star Parties are open to the public and free of charge.  For more information about the St. Louis Astronomical Society visit their website at www.slasonline.org