Week of January 27, 2014

This is the Saint LouisScienceCenter’s NIGHT SKY UPDATE for the week of Monday, January 27.  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 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 7:11 a.m. on Monday, January 27 and sunset is at 5:17 p.m. providing us with roughly 10 hours of daylight.  Even after sunset, the light from the Sun will still illuminate our sky for about one hour and 30 minutes.  This period of time is called twilight, which ends around 6:49 p.m. this week.  For those with a sun dial, solar transit or local noon occurs around 12:14 p.m. this week. 

Moonrise for Monday, January 27 occurs at 3:51 a.m.  Moonset will occur at 2:03 p.m.  On Monday the 20th the Moon will be exhibiting a waning crescent phase with roughly 14% of the lunar disk illuminated.  New moon occurs on Thursday, January 30. 

 

International Space Station (ISS) Observing

 

The next visible passes of ISS over St. Louis are all morning passes.  The best passes are on the mornings of January 28 and 29.  Learn more about the passes and others this week in the table below.

Catch ISS flying over St. Louis in the morning hours starting Monday, January 27. 

 

Date

Mag

Starts

Max. altitude

Ends

Time

Alt.

Az.

Time

Alt.

Az.

Time

Alt.

Az.

27 Jan

-1.9

05:19:04

33

NNE

05:19:11

33

NNE

05:22:14

10

E

28 Jan

 0.1

04:32:54

13

ENE

04:32:54

13

ENE

04:33:24

10

E

28 Jan

-2.9

06:05:50

23

WNW

06:07:36

47

SW

06:10:49

10

SSE

29 Jan

-3.0

05:19:45

64

SE

05:19:45

64

SE

05:22:37

10

SE

30 Jan

 0.0

04:33:44

13

ESE

04:33:44

13

ESE

04:34:08

10

ESE

30 Jan

-1.4

06:06:40

15

WSW

06:07:20

16

SW

06:09:24

10

SSW

31 Jan

-1.2

05:20:45

18

S

05:20:45

18

S

05:21:58

10

SSE

 

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 has started another evening apparition.  About 30 minutes after sunset Mercury will be about 10 degrees above the horizon. The highest altitude Mercury reaches during this apparition is on January 31 when it will reach an altitude of nearly 14 degrees.  Not long after this maximum eastern elongation Mercury will become lost in the glare of the Sun once again.  Take a look at the elusive planet while you can.

Venus

After a short lived absence, Venus has returned to our morning skies for its next morning apparition.  Venus will rise around 5:20 a.m. becoming visible low in the southeast around 6:00 a.m. 

Mars

Mars is now in the constellation Virgo and will rise around 11:16 p.m. this week.  For those awake around 12:30 a.m. look to the east and you will see a reddish-orange object low in the eastern skies.  Mars will be seen earlier each week as we start to catch up with it in our orbit.  Mars will be close to us again in 2014 reaching opposition on April 8, 2014.  Fans of Mars rejoice it is back and on its way to another close approach.

Jupiter

Jupiter is now rising as the Sun is setting.  For those with a clear eastern horizon look east roughly 30 minutes after sunset and you should see Jupiter shining brighter than any star in the sky.  As twilight fades you will see the bright stars Castor and Pollux just north of Jupiter.  Looking at these stars and then comparing them to Jupiter you will see that the stars are twinkling and Jupiter is not.  The twinkling you see is called scintillation which is a distortion of the stars light by Earth’s atmosphere.  Testing for scintillation is how you can distinguish planets from stars. 

Saturn

Saturn is now out of the glare of the Sun.  It rises by 1:49 a.m. and will be an easy target by 3:00 a.m.  Saturn is currently in the constellation Libra.  It forms a nice triangle in the sky with Libra’s two brightest stars Zubenelgenubi and Zubeneschamali.  For those that wake up early go outside around 6:00 a.m., there will be a bright line of planets stretching from the east to west.  Moving from the east you will see Venus just above the southeastern horizon, due south you will see Saturn and now in the west Mars will still be visible. 

 

Additional Solar System Object of Interest

Comet Lovejoy (C/2013 R1): Comet Lovejoy has been a treat for binocular observers since October 2013.  It reached perihelion on December 22, 2013 brightening to about 4.3 magnitude.  It still remains an object of interest for those with binoculars or small telescopes and can be seen in the morning skies by 5:00 a.m.

To locate Comet Lovejoy you will need to find the summer constellation Hercules in the eastern skies.  An easy way to find Hercules is to locate the Big Dipper, follow the curve of its handle to the bright star Arcturus.  This star marks the bottom of the kite shaped constellation Bootes.  Look to the east of the widest part of Bootes kite shape and you first find a U-shape of stars and further down you will see a bowtie shape of stars.  This bowtie shape is the body of Hercules.  Next locate the star Sarin also named Delta Herculis and the star Rasalhague in Ophiuchus.  Comet Lovejoy will be following a path between these stars through most of January 2014.  For a detailed map follow the link below. 

Now that Comet Lovejoy has passed perihelion it will continue to fade becoming more difficult to see each night.  It is currently a 6th magnitude comet that is predicted to fade to 8th magnitude by February 2014.  Take a look at this comet before it fades from view. 

 

General Comet Information

http://cometchasing.skyhound.com/

http://cometography.com/

 

Star Charts Showing Comet Locations in the Sky

http://www.aerith.net/comet/weekly/current.html

http://freestarcharts.com/images/Articles/Month/Dec2013/Comet_Lovejoy/C2013_R1_Lovejoy_Jan_Finder_Chart.pdf

 

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. 

For January the constellation of the month will be Orion the Hunter.  Orion was the great hunter from Greek mythology that was killed by the great scorpion Scorpius.  The pair was immortalized in the sky as constellations and is placed opposite one another in the sky.  Throughout the year you can see both Orion and Scorpius chasing one another as Orion is in the winter sky and Scorpius is in the summer sky. 

Orion is the most prominent constellation in the winter sky.  By the time the Sun is setting Orion is beginning to rise in the southeast.  By 5:30 p.m. Orion has cleared the horizon and the brightest stars are starting to shine through the twilight sky.  Orion has a very distinct hourglass shape with three stars cutting across the middle.  These three stars are Orion’s famous belt and are what most look for when searching for the constellation.  The most prominent stars in Orion are Betelgeuse, Bellatrix, Rigel, Saiph and the three belt stars Mintaka, Alnilam and Alnitak.  Orion will be in the sky from sunset to sunrise and will serve as the starting point for exploring the winter sky. 

The first thing we will explore in Orion is the bright star Betelgeuse.  This star marks the left shoulder of Orion and stands out amongst the rest due to its bright red color.  Betelgeuse is a highly evolved red supergiant star that is beginning the process that ends in a spectacular explosion.  The red color is the result of a core collapse event that allowed the outer layers of the star to expand and cool off significantly until core fusion started again.  Over the next million years or so this process will continue fusing heavier elements each time.  Once the element iron is reached core collapse is inevitable and Betelgeuse will explode in what is called a Type II supernova.  These are rare events as they require a single massive star with a mass of 8 to 50 solar masses.  Stars this big are not common and therefore Type II supernovas are rare events.  In fact in all of recorded history only 6 bright supernovas have been witnessed by humans.  The nuclear fusion process occurring in all stars is how all elements heavier the hydrogen and helium are synthesized.  Fusion can only account for elements up to iron, everything heavier than iron was synthesized during a supernova.  All the precious metals on the earth like those used for jewelry and circuit components were created by the violent explosion of a massive star.    

Betelgeuse is under 10 million years old.  This short stellar life is the result of its mass and temperature.  Betelgeuse was originally a hot massive O or B class star that was associated with the stars in Orion’s belt.  At some point Betelgeuse was ejected from the OB association in Orion’s belt and is speeding away at about 30 km/s. 

To find Betelgeuse look for the bright red star in the top left corner of the constellation.  It will be impossible to miss as it is the 8th brightest star in the sky.  It shines with a magnitude of 0.45 and lies at a distance of roughly 600 light years.  If we put Betelgeuse in our solar system it would be nearly as large as the orbit of Jupiter.  This is a fascinating star that is a great place to start exploring Orion.  Below you will find basic star chart that will assist in finding Betelgeuse and the rest of the targets we will discuss in the following weeks.

http://iau.org/static/public/constellations/gif/ORI.gif 

 

The object for the week of January 13 is the stellar nursery M42 also named The Great Orion Nebula.  Before we talk about this nebula there is another feature of Orion we should discuss.  Doing so will give us a better appreciation for Orion and what is taking place in that part of the sky.  Orion is in a part of the Milky Way known as the Orion Spur.  This is the same part of the Milky Way that the Sun is part of.  In the winter months we are looking at some our nearest neighbors in the galaxy.  Also of interest is that most of Orion is immersed in a molecular cloud of hydrogen dust and a mixed bag of other elements.  This cloud is known as the Orion Molecular Complex and it is an area in the Milky Way that acts as a cauldron for star formation.  Most of the brightest stars in Orion are the products of this giant molecular cloud.  Most of these bright stars have formed over the last 12 million years.  The brightest of these stars are O and B class stars and when they exhibit the same proper motion they are called an OB Association.  Collectively Orion has what is called the Orion OB1 association.  This is made up of four distinct age groups known as OB1a, OB1b, OB1c and OB1d.  The oldest of these groups is OB1a at 12 million years old and the Newest is OB1d at an age of roughly 30,000 years old.  There is some data that suggests the youngest members of OB1d are only 10,000 years old.  These are stars that fit inside the recent history of humankind.  The oldest identified culture in North American is the Clovis culture.  They were an early nomadic culture that existed roughly 10,000 to 13,000 years ago.  It is likely within this cultures existence that the youngest stars in the OB1d association first started to shine. 

And this brings us to our object of the week M42.  The stars in the OB1d association all came from the bright emission nebula M42.  This is currently the most active star forming region in the Orion Molecular Complex and it is still actively producing stars.  To find M42 look for what appears to be three stars in a line perpendicular to and below the belt of Orion.  Scanning the central of these stars with a pair of binoculars you will quickly see that there are more than just three bright stars.  M42 will stand out as a large dim patch of greyish light with what looks like a dark finger poking into the object.  Sadly the human eye is not sensitive enough to perceive the color of this nebula as it has a bright pinkish color.  The color seen in emission nebulae is caused by the young hot stars exciting the gasses in the nebula through a process called ionization. 

The group of stars that is mainly responsible for the ionization of M42 can be seen through a small telescope and are known as the Trapezium Cluster.  They will appear to be four stars arranged in a trapezoid shaped and are the brightest components of the OB1d association discussed above.  Larger telescopes will be able to reveal a few more stars that are members of this small cluster of stars.  The Trapezium Cluster is so young that many of its members are either still shrouded in the gasses and dust of M42 or are still actively forming.  Many these stars are only visible using telescopes like the Hubble or others that have the ability to observe in the infrared wavelength of light. 

If you have ever wondered about how stars form, M42 and the rest of Orion is the best example of this process we can see in the northern hemisphere.  The rest of the objects we will cover this month will all be members of the Orion Molecular Complex.  Some will be more of the young star clusters that have formed over the last 12 million years and one will be a cloud of dust and gas that is visible due to reflected star light.  Orion is a favorite constellation for many.  He has huge cultural significance, he is bright and easy to find and lastly he will keep even the most avid stargazer busy due to the numerous deep sky scattered through the constellation.  Below you will find link to a star chart for Orion and a link to the Hubble Space Telescope website. 

http://iau.org/static/public/constellations/gif/ORI.gif

http://hubblesite.org/search/?query=M42

 

The Object for the week of January 20 is the star cluster Collinder 70 (Cr70).  This is an open star cluster in which roughly 80 stars can be seen when observed through a pair of binoculars.  The brightest stars in the cluster are easily seen as they are the three belt stars of Orion.  Like M42 and the stars in that nebula, the stars of Cr70 are products of the Orion Molecular Complex and the Orion OB1b association.  The stars in the Orion OB1 Association are roughly 8 million years old and are roughly 700 to 1500 light years away.

Finding Cr70 is simple, just find Orion’s Belt.  Once you can find this famous asterism grab a pair of binoculars and start slowly scanning from side to side of the belt and you will easily see that there is more than just three bright stars in that part of the sky.  For those with dark skies and a telescope you can try to spot the Flame Nebula and Horsehead Nebula near the star Alnitak.  The Flame Nebula also named NGC 2024 is an emission nebula that is glowing due to the hot UV radiation from Alnitak as it sweeps by the cloud of hydrogen gas ionizing it in the process.  The Horsehead Nebula is a dark nebula that stands out amongst the glowing ionized gasses of NGC 2024.

 

The final object we will explore in Orion is the reflection nebula M78.  Like the other objects discussed this month M78 is part of the large complex of dust and gas scatter throughout the constellation of Orion.  M78 is a stellar nursery like M42 but we see it for a different reason.  M78 is a mixture of dust and gas like M42 but the glow we see is not from the gasses in the nebula being ionized but rather the light from young and hot blue stars in M78 is being reflected by the dust in the nebula. Visual light and infrared images show a cluster of young stars scattered through the nebular complex.  A little over 40 stars have been observed visually and roughly 180 stars have been observed using infrared observations. 

Scattered around M78 are a number of other nebular complexes, NGC 2064, 2067, and 2071.  Another object that is fascinating is called McNeil’s Nebula.  This is small reflection nebula that surprised observers in 2003 when it became visible.  As it turns out this structure had been photographed before indicating it has a variation in its brightness.  This variable nebula is called a Herbig-Haro Object and is likely a star that is still in its formation process.

To find M78 and all of the other things listed with it first locate the three belt stars.  Look about 2 degrees northeast of the left most star in Orion’s belt.  Through binoculars you will see a faint comet like fuzzy patch of light.  Small telescope will reveal the nebulous patch and with good seeing conditions perhaps a few of the stars in the cluster of M78 and a few of the other surrounding nebulas.  Follow the links below to learn more about M78 and the other nebulas nearby.

http://iau.org/static/public/constellations/gif/ORI.gif

http://messier.seds.org/m/m078.html

 

Supernova in M82

Recently a supernova was discovered in a neighboring galaxy called M82 or The Cigar Galaxy.  This galaxy is roughly 12 million light years away and is a member of the M81 group of galaxies.  The first to realize a star exploded in this galaxy were some astronomy students and their teacher who were exploring how to use a CCD camera to image the night sky.  There was a bit of astronomical serendipity as their observing session was being encroached upon by a bad weather.  Due to the approaching weather they had limited options for what to observe.  They chose M82 and were pleasantly surprised when they saw a star like object that normally is not seen in the galaxy.  Upon investigation they realized they had discovered a new supernova which is now designated Supernova 2014J.

Spectral analysis of the supernova shows a strong signature of silicon.  What this tells astronomers is that this is a Type Ia supernova.  This type of supernova involves two stars one of which is on its main sequence and the other is a white dwarf star.  White dwarf stars are the dense core of a star like the Sun that has evolved off its main sequence and is now fusing carbon and oxygen.  The by product of this is silicon.  As the white dwarf star orbits with its partner star it siphons material from its partner.  Due to the temperatures and pressures that develop, only 1.4 solar masses can be taken in this way.  Once it reaches this limit the star will explode in a supernova.  Type Ia Supernova like Supernova J2014 are useful to astronomers for measuring the distances to objects in space.  Since there is a set amount of mass that is gathered before the supernova there is a known amount of energy that is released.  With this they can determine the absolute luminosity and there for measure how far away the event is. 

To find M82 first locate the Big Dipper.  Follow a line from the stars Phecda to Dubhe and continue another roughly 10 degrees along this path.  Through a small telescope you will see two faint and fuzzy objects which are the galaxies M81 and M82.  Once you have located M82 you will need to carefully observe the fuzzy light source and you will see a faint star like object on its right side.  This is Supernova J2014.  Right now it is a safe bet that you will likely need a 6-inch telescope but the supernova may brighten enough to be within reach of 4-inch instruments.  If you find the supernova you will be looking at light from an explosion that occurred 12 million years ago as M82 is 12 million light years away.  Follow the links below for more information and a map of Ursa Major to help you locate M82 and Supernova J2014.

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

http://www.skyandtelescope.com/observing/home/Bright-Supernova-in-M82-241477661.html

          

Our next Star Party will be held on Friday, February 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 February 7, join us indoors in our planetarium theater for “The Sky Tonight”.  Showtime is at 7 p.m.  There will also be two Laserium shows this night at 8:30 p.m. and 10:00 p.m.  Information for laser shows can be found at http://www.slsc.org/laserium

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

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