Week of March 3, 2014

This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Monday, March 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, March 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, March 3 and sunset is at 5:56 p.m. providing us with over 11 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 7:24 p.m. this week.  For those with a sun dial, solar transit or local noon occurs around 12:13 p.m. this week.    

Moonrise for Monday, March 3 occurs at 7:42 a.m.  Moonset will occur at 8:57 p.m.  On Monday the 3rd the Moon will be exhibiting a waxing crescent phase with roughly 8% of the lunar disk illuminated.  First quarter moon occurs on March 8.   

International Space Station (ISS) Observing

ISS will not be visible again until the beginning of next week.  However this week is loaded with visible passes of the Hubble Space Telescope.  This satellite is normally low in the south so it can be difficult to see.  Below you will find a few of the best passes.  For more information regarding HST and other satellites visit www.heavens-above.com  

Catch HST flying over St. Louis in the evening hours starting Monday, March 3. 

Date

Mag

Starts

Max. altitude

Ends

Time

Alt.

Az.

Time

Alt.

Az.

Time

Alt.

Az.

04 Mar

 2.7

18:35:39

10

SW

18:38:43

20

S

18:41:47

10

SE

05 Mar

 2.7

18:29:23

10

SW

18:32:31

20

S

18:35:39

10

SE

06 Mar

 2.8

18:23:10

10

SW

18:26:18

20

S

18:29:26

10

SE

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 clockewise 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 morning apparition.  Mercury rises around 5:30 a.m. so if your southeastern skies are clear you should see Mercury just below and to the left of Venus after 6:00 a.m. 

Venus

Venus has started its next morning apparition. It rises around 4:07a.m. becoming easily visible by 5:00 a.m.  For those awake at this time you will see Venus, Saturn and Mars stretching across the southern skies.  This planetary display nicely represents the path that the planets, Sun and Moon follow.  This path is called the ecliptic.

Mars

Mars is now in the constellation Virgo and will rise around 9:24 p.m. this week.  For those awake around 11:30 p.m. look to the east and you will see a reddish-orange object 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 stars from planets. 

Saturn

Saturn is now out of the glare of the Sun.  It rises by 11:32 p.m. and will be an easy target by 12:30 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.

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. 

The constellation for the month of March is Virgo.  Virgo is one of the twelve constellations of the zodiac.  These constellations were created to track what ancient astronomers thought were wandering stars.  Today we know that the objects they were observing are planets and our modern name for these objects is a derivative of the ancient term Aster Planetae.  What defines Virgo as zodiacal is what is called the ecliptic.  The ecliptic is the path that the Sun, Moon and planets appear to follow in the sky.  Any constellation that crosses this path is considered zodiacal.  Right now Virgo is where you can find Mars rising a little before 10 p.m. 

In Greek mythology Virgo was associated with the goddess of justice Astraea and the maiden of the harvest Persephone.  In the tale of Persephone, Virgo represented the daughter of Demeter and was tricked into marrying the god of the underground Hades.  Demeter was so distraught over the loss of her daughter to the underworld she pleaded with the rest of the gods to allow her daughter to return home.  The gods agreed allowing Persephone to return for 1/3 of the year.  The return of Persephone was associated with the spring months in which the return of the maiden would bring life back to the Earth following the dreary winter months.

Virgo is the second largest constellation in the sky.  It contains 20 stars that have been discovered to have planets of their own and it is also loaded with distant galaxies and other deep sky objects.  In Virgo alone there are 12 messier objects most of which many are members of the Virgo Galaxy Cluster.  This month we will go on a tour of Virgo visiting a few galaxies and few other objects of interest. 

Our first object we will talk about is the star 70 Virginis.  Like I said at the end of last month’s night sky update, I wanted to include various stars of interest.  70 Virginis will be the star for Virgo.  This is a yellow dwarf star that has a temperature of about 5400 kelvins which is a bit cooler than the Sun.  It is a little bigger than the Sun at 1.12 solar masses and has a luminosity that is three times higher than the Sun’s.  When all is said and done, this star is similar to the Sun in most regards.  Another feature that is similar to the Sun and is the reason I am including it in this month’s night sky update is 70 Virginis has a planet.  This was one of the first stars other than the Sun to be discovered to have a planet of its own.  The discovery was made in 1996 and was just one of many that would be discovered over the next few decades.  The current exoplanet count is at 1,690 confirmed and another 3,845 candidates.  We have come a long way since 1996 and based on the current number, it is estimated that the Milky Way which contains an estimated 200 billion stars likely has that many if not more planets.  It has also been discovered that 70 Virginis has a disk of material that lies about 3.4 astronomical units from the star. 

70 Virginis lies about 59 light years away in the northern section of Virgo.  It is a 5th magnitude star that for most will require a pair of binoculars to see.  To find 70 Virginis start at the Big Dipper and follow the curve of the handle to the star Arcturus in the constellation Bootes.  From there continue along the curve until you see a bright blue white star and a bright reddish orange star like object.  The blue white star is Spica and the reddish orange object is the planet Mars.  Next look above Spica and find the bright stars Zeta, Gamma (Porrima) and Epsilon (Vindemiatrix) Virginis.  These stars along with Spica form rhombus shape.  Looking east of Epsilon Virginis about 7 degrees you will see two bright stars that are vertically 4 degrees apart.  The top star is 70 Virginis.  On the map linked below 70 Virginis is the northern most star in the constellation.

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

Our next Star Party will be held on Friday, March 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 7:00 p.m.  Regardless of the weather on March 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

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