The Night Sky a Close Mercury/Jupiter Conjunction This Month
Total Page：16
File Type：pdf, Size：1020Kb
The Night Sky A Close Mercury/Jupiter Conjunction this Month Planet Venus remains low along the west-southwester horizon this month shortly after sunset. However it is very easy to spot it in the bright twilight due to its brilliance. On October 3rd, a thin crescent moon sits above Venus. For those with keen eyesight, one might be able to notice a star, very close to the upper left of Venus on this date. This star is Alpha Librae, the second brightest star in the constellation of Libra. This stellar system is interesting since it is a quintuple stellar system (5 stars), lying 77 light years from our solar system. Venus will be moving very quickly against the background stars this month. By the end of the month, Venus passes between planet Saturn and the red supergiant star Antares, similar to what Mars did during the last week of August. On October 27th, Antares, Venus, and Mars are aligned in a straight line rising up above the southwestern horizon. Planet Mars continues its relatively rapid motion eastward across the sky as well, as it maintains its decrease in brightness as the earth pulls away from our red neighbor. Mars starts the month on the western side of Sagittarius, and move across most of this constellation during October. On October 6th, Mars passes just 0.2-degrees to the south of Lambda Sagittarii, the top star of the Sagittarius Teapot asterism. For you early risers, Mercury and Jupiter have a very close conjunction on the morning of October 11th. About one-half hour before sunrise, look for this pair 5-degrees above the eastern horizon. Mercury will be on the left-hand side of slightly brighter Jupiter. As the month progresses, Mercury continues to sink and leaves the morning sky. Meanwhile, Jupiter continues to climb, rising almost two-and-a-half hours before the sun at month’s end. The moon will be at full phase at 12:33 a.m. EDT on October 16th. A few nights after this on the night of October 18-19, the moon passes in front of the red giant star Aldebaran in Taurus. This occultation begins around 1:20 a.m. EDT on the 19th and ends around 2:30 a.m. The moon will be in a waning gibbous phase during this occultation, which means that this bright red giant star will pop into view on the dark side of the moon when the occultation ends. Let’s hope for a clear sky on that night. The next free public astronomy open house at the ETSU Powell Observatory will occur on Saturday, October 8th from 8 to 10 p.m. At these open houses, the public can view objects in the sky through telescopes and hear talks by faculty of the Physics and Astronomy Department. Note that the open houses are cancelled if the sky is cloudy. Further information about these open houses and directions to the observatory can be found on the web at http://www.etsu.edu/cas/physics/observatory/default.aspx. This month’s Night Sky was written by Dr. Donald G. Luttermoser, Chair of the Department of Physics and Astronomy at ETSU. He can be reached at [email protected]. Astronomy-related information for the public, including a link to the ETSU Powell Observatory, can be found at http://www.etsu.edu/cas/physics/ by selecting the Public Outreach pull down menu at the top of this web page. .