This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Friday, January 22, 2020.

Information updated weekly or as needed.

Times given as local St. Louis time which is Central Standard Time (CST). For definitions of terminology used in the night sky update, click the highlighted text. If relying on times posted in Universal Time (UT), St. Louis is now -6 Hours from UT.

Public Telescope Viewings

Star parties at the Saint Louis Science Center have temporarily been canceled due to recommendations from the CDC regarding COVID-19. All public telescope events are canceled until further notice. As conditions change, we will reevaluate and update this article once public observing events resume.

Constellation Auriga the Charioteer
Credit: Stellarium, EG

Observing Highlight of the Week

This week we will cover the constellation Auriga the Charioteer. Auriga is one of the brighter constellations in the winter sky and is easily found due to its proximity to the constellations Orion. Its brightest starts make-up a 5-sided shape that looks like a house or home plate. The brightest star in the constellation is called Capella which is the northern most star that makes up the asterism called the Winter Circle.

Auriga offers several easy targets for binocular viewers. Three of which are the open star clusters M36, M37 and M38. Open star clusters as defined by the Center for Astrophysics; Harvard and Smithsonian, “are collections of stars with similar ages, chemical compositions, and distances from the Sun”. The idea is that they form from the same source material and are important for studying the formation of stars, their evolution and other fundamental astrophysics. Reference the image above or the constellation map linked at the start of this section for the location of M36, M37 and M38.

Another interesting target for binocular viewers is the asterism called the Minnow. This is a group of stars that appear as a vertical line in the middle of the southern half of Auriga. Not all groups of stars we see are star clusters, but they still offer a nice view and a means to improve our observational skills. The brightest members of this asterism are the stars, 14, 16, 17 and 19 Aurigae. If you can find this group of stars, M38 is located next to it as is the runaway star known as AE Aurigae. This O-type star is called a runaway because it is moving at an abnormally high velocity. It is thought the AE Aurigae behaves this way due to a collision between two binary stars that occurred in the constellation Orion about 2 million years ago.

For those with a telescope and dark skies, the star AE Aurigae is passing through a nebula called IC 405 or the Flaming Star Nebula. This nebula is visible because AE Aurigae is exciting hydrogen atoms in the nebula which results in the atoms releasing a photon. Due to this, IC 405 is an emission nebula. It makes for a nice target in telescopes, but it really comes alive for astrophotographers.

As winter presses on, Auriga makes for a nice addition to our list of winter targets. The next clear night we get, grab those binoculars and check out the numerous offerings the Charioteer has to offer.

The Sun and Moon


The Moon as seen from the International Space Station, on July 31, 2011.
Credit: NASA

Sunrise is at 7:14 a.m. on Friday, January 22 and sunset is at 5:12 p.m. providing us around 10 hours of daylight. Even after sunset, the light from the Sun will dimly illuminate our sky for about 1 hour and 30 minutes. This period is called twilight, which ends around 6:44 p.m. this week. For those with a sundial, local noon occurs around 12:13 p.m. this week.

DaySunriseSunset
2021-01-227:14 a.m.5:12 p.m.
2021-01-23 7:13 a.m.5:13 p.m.
2021-01-24 7:13 a.m.5:14 p.m.
2021-01-25 7:12 a.m.5:15 p.m.
2021-01-26 7:11 a.m.5:17 p.m.
2021-01-27 7:11 a.m.5:18 p.m.
2021-01-28 7:10 a.m.5:19 p.m.
2021-01-29 7:09 a.m.5:20 p.m.
2021-01-30 7:08 a.m.5:21 p.m.

Moon 

Moonrise for Friday, January 22 occurs at 12:24 p.m. and moonset will occur at 1:47 a.m. on the following day. On Friday, January 22 the Moon will exhibit a waxing gibbous phase with 66% of the lunar disk illuminated. Full moon occurs on January 28 at 1:16 p.m.

International Space Station (ISS) Observing

Credit: NASA

Visible passes of ISS from St. Louis for the week of January 22 occur during evening hours. The best pass this week occurs on the evening of January 22. Use the table below for information about this and other visible passes this week.

Catch ISS from St. Louis starting Friday, January 22

Date Starts  Max. altitude  Ends  
TimeAlt.Az.TimeAlt.Az.TimeAlt.Az.
22 Jan-2.5 17:52:3410W 17:55:4234NNW 17:58:5010NE
23 Jan-1.3 18:43:5210NW 18:45:4014NNW 18:46:3812N
24 Jan-1.5 17:55:4210WNW 17:58:0317NNW 18:00:2410NNE

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 Visible Planets


Looking Southwest, at 5:45 pm, January 22, 2020
Credit: Stellarium, EG, WS


Looking Southeast, 7:00 am, January 23, 2020
Credit: Stellarium, EG

This week, three naked eye planets are visible. Mercury is found in the southwest and Mars is found high in the south after sunset. Venus can be found in the southeastern sky before sunrise.

Mercury

Mercury is exhibiting its first evening apparition of 2021. The elusive planet will become easier to see as the week progresses. As Mercury heads towards greatest eastern elongation on January 23 the planet will be seen higher above the southwest horizon each night. Head outside about 40 minutes after sunset and look to the southwest to locate this elusive planet.

Venus

Venus rises at 6:25 a.m. and will be visible around 7:00 a.m. Venus remains a morning object until March 26, 2021 when it reaches superior conjunction. Since Venus has passed greatest western elongation, it is exhibiting a gibbous phase.

Mars

Currently Mars appears as a 0.3-magnitude object that will be visible high in the south about 30 minutes after sunset. Mars sets by 1:01 a.m. We are still near enough to Mars that surface features are visible through telescopes. Earth is moving away from Mars which means Mars is getting fainter each night. The observing season for this apparition ends around March 10, 2021 and superior conjunction occurs on October 7, 2021.

Uranus

Uranus is not a planet we normally include in this section. Even at its dimmest, the giant planet does hover within naked eye visibility. That said, it is so close to the visible limit of the human eye it just is not reality for most of us to see Uranus without binoculars or a telescope. You can find Uranus in the constellation Aries the Ram. The current magnitude for Uranus is 5.8. A finder chart for Uranus can be found here.

James S. McDonnell Planetarium

Night Sky Update: January 22-January 30, 2020