This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Tuesday, June 28.  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, July 1, 2016 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 5:39 a.m. on Tuesday, June 28 and sunset is at 8:30 p.m. providing us with nearly 15 hours of daylight.  Even after sunset, the light from the Sun will still dimly illuminate our sky for nearly two hours.  This period of time is called twilight, which ends around 10:27 p.m. this week.  For those with a sun dial, solar transit or local noon occurs around 1:04 p.m. this week.




 28 Jun

5:39 a.m.

8:30 p.m.

 29 Jun

5:40 a.m.

8:29 p.m.

 30 Jun

5:40 a.m.

8:29 p.m.

 01 Jul

5:40 a.m.

8:29 p.m.

 02 Jul

5:41 a.m.

8:29 p.m.

 03 Jul

5:42 a.m.

8:29 p.m.

 04 Jul

5:42 a.m.

8:29 p.m.

 05 Jul

5:43 a.m.

8:29 p.m.

 06 Jul

5:43 a.m.

8:28 p.m.


Moonrise for Tuesday, June 28 occurs at 1:18 a.m. and moonset will occur at 2:11 p.m.  On June 28 the moon will be exhibiting a waning crescent phase with about 39% disk coverage.  New moon moon occurs on Monday, July 4.

International Space Station (ISS) Observing

There are no visible passes of ISS from St. Louis this week.  ISS will return to St. Louis skies on July 7.  Instead try finding the Hubble Space Telescope (HST).  Below you will find the best four passes for this week.  All listed occur in the evening hours.

Catch HST flying over St. Louis starting Tuesday, June 28.

Date Mag


Max. altitude


Time Alt. Az. Time Alt. Az. Time Alt. Az.
02 Jul  2.3 21:42:15 10 SW 21:45:12 19 S 21:46:01 18 SSE
03 Jul  2.3 21:32:23 10 SW 21:35:24 20 S 21:36:56 16 SSE
04 Jul  2.3 21:22:33 10 SW 21:25:37 20 S 21:27:45 14 SE
05 Jul  2.4 21:12:47 10 SW 21:15:49 20 S 21:18:30 11 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 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

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

The Planets Visible Without a Telescope


The Red planet is currently found in Libra rising before the Sun and can be easily seen by 9:30 p.m. in the southeastern sky.  Mars sets by 2:45 a.m.


Jupiter now rises before the Sun sets. To see Jupiter you will have to look high in the west at about 8:50 p.m.  Jupiter sets at 12:10 a.m.  Each week Jupiter will set approximately 30 minutes earlier than it did the week before.

NASA’s Juno mission will arrive at Jupiter on Monday, July 4.  Juno’s primary mission will start with Jupiter orbital insertion on July 4, 2016 and will end when the spacecraft is deorbited allowing the spacecraft to descend into the crushing atmosphere of Jupiter in February 2018.  Over 20 months Juno will complete 37 orbits during which the spacecraft will investigate Jupiter’s core and magnetic field, measure the amount of ammonia and water in Jupiter’s deep atmosphere and it will observe the planet’s aurora and charged particle environment.  Orbital insertion and mission coverage begin at 9:30 p.m. on NASA TV.


The ringed planet is has reached opposition and as such rises before the Sun sets.  Look for Saturn alongside Mars in the southern sky about 30 minutes after sunset.  Saturn will set by 4:08 a.m.

Deep Sky Object of the Week

A few years ago 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.  In 2015 we changed things a bit for this section and instead of highlighting one constellation for each month we highlighted one Messier object a week using the Astronomical League’s Binocular Messier program as our guide.  We will continue this into 2016 but instead of using the Astronomical League’s binocular Messier program we will use their Binocular Deep Sky Program.

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

The observing program we will use to help guide us through the 2016 observing year is the Binocular Deep Sky 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 deep sky program is an introduction to deep sky objects beyond the Messier catalog.  It will introduced viewers to the New General Catalog (NGC) and some of the lesser known deep sky catalogs such as the Stock, Collinder and Melotte.  Each week we will highlight a deep sky object that is part of the Astronomical League’s binocular deep sky program.  This program is tougher than Messier binocular program as the objects are not always as obvious and they will require larger binoculars than the Messier program.  50mm binoculars are recommended but many of the targets can be seen through smaller aperture instruments.  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 deep sky object for the week of June 7 is the open star cluster NGC 6709.  Located in the constellation Aquila, NGC 6709 will be seen rising in the east by 11:00 p.m.  At a distance of 3,000 light years NGC 6709 shines with an apparent magnitude of 6.7.  This star cluster contains 60 stars that are estimated to be roughly 78 million years old.  The Trumpler classification for NGC 6709 is III, 2, m which means it is well detached from background stars with no central classification, it has a moderate range of stellar magnitudes and it has a moderate population with between 50 and 100 stellar members.

To find NGC 6709 start by looking for the Summer Triangle.  The Summer Triangle can be found by looking east around 11:00 p.m.  It is made up of the bright stars Vega, Deneb and Altair which are found in the constellations Lyra, Cygnus and Aquila respectively.  Aquila will look like an elongated diamond shape of stars that makes up the southernmost portion of the Summer Triangle.  Once you can identify the star Altair look about 12 degrees to the west and you will see the western tip of the diamond shape which are the stars Zeta and Epsilon Aquilae.  Once you can find these stars look about six degrees to the south and you will find NGC 6709.  Use the maps below to find this week’s star cluster.

The deep sky object for the week of June 14 is the open star cluster NGC 6716.  This open cluster is found about 2,000 light years from the Earth in the constellation Sagittarius.  At this distance it shines with an apparent magnitude of 6.9 and will appear as a large dim scattering of stars.  There are only about 20 stars in NGC 6716 that are estimated to be only 160 million years old.  When these stars first started to shine the supercontinent Pangea was breaking apart to form the northern supercontinent Laurasia and the southern supercontinent Gondwana.  NGC 6716 has a Trumpler classification of IV, 1, p which means it is not well detached from background stars, its stellar members have very little variation in stellar magnitudes and it has a poor population of stars containing less than 50 members.

To find NGC 6716 you will have to locate the constellation Sagittarius which can be found in our southern skies around midnight.  An easy way to find Sagittarius is to start with Scorpius.  This constellation is just west of Sagittarius and looks like a large fishhook shape of stars.  Once you can see this look east for the Teapot asterism and you will find Sagittarius.  Once you have found Sagittarius look for the star Sigma Sagittarii in the teapot’s handle.  Once you identify this star grab your binoculars and scan north about six degrees until you find the stars Xi1 and Xi2 Sagittarii.  From these stars NGC 6716 is another couple degrees north.  Use the maps below to help find the guide stars and use Stellarium to help pinpoint the star cluster NGC 6716.

The deep sky object for the week of June 21 is the asterism known as Collinder 399 also known as the Coat Hanger asterism.  Most groups of stars we talk about in this section will be physical grouping of stars that move together.  Periodically star clusters are named but later analysis determines they are not true clusters but rather are simply chance alignment of stars.  This is the case with our object this week called Collinder 399.

Located in the constellation Vulpecula, Collinder 399 was discovered by Persian astronomer Al Sufi in 964 CE.  Up until the 1970s most thought it was a cluster of roughly 30 stars.  Once more accurate surveys such as the Hipparcos survey was complete it became clear is was not.  Regardless of its designation Collinder 399 is still a nice group of stars to observe.

Collinder 399 is located in the summer constellation Vulpecula the Fox.  This is seen rising in the east after 10:00 p.m.  To find Collinder 399 you will want to locate the bright stars Altair in Aquila and Vega in Lyra.  If you grab your binoculars and scan from Altair to Vega you will find Collinder 399 about 1/3 of the way to Vega.  It will appear as a bright upside down coat hanger.  Use the maps below for assistance.

The deep sky object for the week of June 28 is the open star cluster NGC 6819.  NGC 6819 is a group of roughly 150 stars that can be found in the constellation Cygnus the Swan.  At a distance of 7,200 light years this star cluster shines with an apparent magnitude of 7.3.  Light pollution will give this star cluster a little trouble for binocular observers but you should be able to notice a nebulous patch of light where the star cluster is found.  As open star clusters go NGC 6819 is considerably old at an estimated age of 2.5 billion years.  It has a Trumpler classification of I, 1, r meaning it is well detached from background stars with a strong central concentration, it has little variance in stellar magnitudes and it has a rich population having over 100 stars.

To find NGC 6819 you need to locate the constellation Cygnus the Swan.  To do this look east after 10:00 p.m. and you will see the three bright stars of the Summer Triangle; Deneb, Vega and Altair.  These stars can be found in constellations Cygnus, Lyra and Aquila respectively.  Once you find Deneb in Cygnus look south for the next bright star called Gamma Cygnii and then follow his west wing to the star Delta Cygnii.  Once here grab your binoculars and scan about 4 degrees south until you see a fuzzy nebulous patch of light which is NGC 6819.  Use the links below for assistance in locating this week’s object NGC 6819.                                               

Our next Star Party will be held on Friday, July 1, 2016, 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 once it is dark.  Regardless of the weather on July 1, 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.