Week of January 20, 2014

This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Monday, January 20.  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 7:15 a.m. on Monday, January 20 and sunset is at 5:09 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 6:42 p.m. this week.  For those with a sun dial, solar transit or local noon occurs around 12:12 a.m. this week.    

Moonrise for Monday, January 20 occurs at 9:41 p.m.  Moonset will occur at 9:49 a.m. on the following day.  On Monday the 20th the Moon will be exhibiting a waning gibbous phase with roughly 82% of the lunar disk illuminated.  Last quarter moon occurs on Tuesday, January 23. 

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 26 and 27.  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 20. 





Max. altitude











22 Jan











23 Jan











24 Jan











25 Jan











26 Jan











27 Jan












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



The closest planet to the Sun has started another evening apparition.  About 30 minutes after sunset Mercury will be a little less than 7 degrees above the horizon.  For most of us that will still be too low for us to see the planet but if you can find clear western horizon you might be able to find Mercury with binoculars.  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.


Mars is now in the constellation Virgo and will rise around 11:06 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 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 is now out of the glare of the Sun.  It rises by 1:35 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.

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



Star Charts Showing Comet Locations in the Sky




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.


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.           

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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