Today: Do you see a hunter when you look at Orion, due south at 7:30 p.m.? The bright reddish star Betelgeuse, five fists above due south, and Bellatrix, the bright bluish-white star one fist to the right of Betelgeuse, are the broad shoulders of the hunter. The bright bluish-white star Rigel and Saiph, the bright star to the left of Rigel, represent the knees. The Maya saw the equilateral triangle formed by Rigel, Saiph, and the left-most belt star as the “Three Stones of the Hearth”. The Orion Nebula is in the center of the hearth and it represents the flame, called K’ak.
Sunday: Even though Zubenelgenubi is the second brightest star in Libra, its name means Southern Claw in Arabic, an artifact of the time that it was considered part of Scorpius the scorpion. Zubenelgenubi is a visual binary, consisting of a white and yellow star that are about arc minutes apart from each other in the sky. This is about the same angular diameter of a medium sized dark spot, or mare, on the Moon and can be observed with the naked eye under good sky conditions. In actuality, they are at least 5,500 astronomical units apart from each other, about 130 times the distance between the Sun and Pluto. Zubenelgenubi is two fists above the south-southwestern horizon at 5:30 a.m.
Monday: Venus is one fist above the southeastern horizon at 5:45 a.m. Mars is a half a fist below it.
Tuesday: Did you get binoculars for the holidays? Like for President’s Day or Martin Luther King, Junior Day? If so, start using them on some top binocular targets found here: http://tiny.cc/5d4rtz. The first item on the list, the Moon, is a great choice this week because it is close to the first quarter phase meaning it is visible from sunset to midnight. One of my favorite binocular objects is the Hyades Open Star Cluster, a fist to the left of the moon. It is a V-shaped set of stars. The bright star Aldebaran is in the upper left hand corner. Just below Aldebaran is the double star system Theta1 and Theta2 Tauri.
Wednesday: The bright star Spica finally makes an appearance in the evening sky. It is one and a half fists above the east-southeastern horizon at 11:00 p.m.
Thursday: If you ask an astrobiologist for the three most likely places to find evidence of life in the Solar System, other than Earth, they’d probably say Mars, Europa (“Didn’t they sing “The Final Countdown”?”), and Enceladus. Mars makes sense because you know scientists have sent a lot of probes there. Enceladus, one of Saturn’s moons, is an up and coming interest that first piqued astrobiologists’ interest a few years ago when NASA’s Cassini probe discovered jets of water containing organic materials shooting out. Between the pop culture alien hot spot of Mars and the new favorite is Jupiter’s moon Europa. Astronomers first discovered strong evidence of a large water ocean on Europa in 1989 during a Galileo flyby. In the next five years, NASA and the European Space Agency (ESA) will be sending spacecraft to Europa. For a preview of the ESA JUICE mission and the NASA Europa Clipper mission, go to https://youtu.be/dAW2uPPS2A4.
Friday: Are you lonesome tonight? Alphard in the constellation Hydra is. Also spelled Al Fard, Arabic for “the solitary one”, Alphard is in a region of the sky without any bright stars. Alphard really ought to have a lot of friends. It is an orange giant star like better known stars such as Arcturus and Aldebaran. It pulsates, making it interesting to astro-seismologists. And it is on the flag of Brazil. There’s no reason for it to be lonely. Go introduce yourself to Alphard, three and a half fists above due south at 10:00 p.m.
The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to https://nightsky.jpl.nasa.gov/planner.cfm.
