Saturday: “You know Aries and Cancer and Draco and Libra. Leo and Pisces and Virgo and Hydra. But, do you recall, the pointiest asterism of all? Triangulum, the three sided asterism, had a very pointy shape. And if you didn’t know it, you would say it poked an ape.” Sorry. Some stores have started sending out their Christmas catalogues and that has put me in the mood to modify some Christmas songs. Anyway, Triangulum is a small constellation between the more prominent Andromeda and Aries. Its main feature is a skinny triangle oriented parallel to and nearly four fists held upright and at arm’s length above the eastern horizon at 11:00 p.m.
Sunday: Fomalhaut, the southernmost bright star visible from the northern USA, is one fist above the south-southeastern horizon at 11 p.m. In 2008, Fomalhaut and its surroundings became the first star system with an extrasolar planet to be directly imaged https://apod.nasa.gov/apod/ap081114.html.
Monday: The waning crescent Moon, Venus, and the Beehive Cluster make a small triangle in the sky this morning. They are about two and a half fists above due east at 5:30 a.m. The Beehive Cluster, described by Ptolemy as “a nebulous mass in the breast of Cancer [the crab]”, is about a thumb-width above Venus.
Tuesday: Jupiter and Saturn are about two fists above due south at 9:00 p.m. Jupiter is the much brighter of the two. Saturn is about a fist to the left of Jupiter. When you are looking at this part of the sky, you are looking in the direction of more than just the two planets. You are also looking in the direction of their moons. Titan, Saturn’s largest moon, is easily visible with a small telescope, about five “ring diameters” to the side of Saturn at this time. Jupiter’s four largest moons are also visible with a small telescope. Callisto and Ganymede are on one side of Jupiter, with Ganymede appearing the farthest away. Europa is visible in the other. If you have very clear skies, you may see Io on the Europa side, right next to Jupiter. Recently, a team of Canadian astronomers analyzed images of Jupiter from 2010 and estimated that Jupiter could have 600 moons at least 800 meters, a half mile, in diameter. They didn’t actually discover these moons. They just formulated a possible model of the Jovian system. For more on this, go to https://skyandtelescope.org/astronomy-news/jupiter-could-have-600-moons/.
Wednesday: In 1987, the rock group Def Leppard sang “Pour some sugar on me, in the name of love. Pour some sugar on me, come on fire me up”. In 2012, some European astronomers “found some sugar near stars, they were very young. Found some sugar near stars, out where planets formed.” Astronomers observed molecules of glycolaldehyde, a simple form of sugar, in the disk of gas and dust orbiting young binary stars. This is the first time astronomers have found this simple sugar so close to a star indicating that organic molecules can be found in planet-forming regions of stars. For more information, go to http://goo.gl/tfwy1.
Thursday: Mars is about two fists above the eastern horizon at 11:00 p.m.
Friday: Earlier this week, you read about Fomalhaut, the second brightest star with a planet. The brightest star known to have a planet is Pollux, in the constellation Gemini. (First and second brightest is meaningless here because they are nearly identical in magnitude, 1.15 vs. 1.16.) Pollux is four and a half fists above due east at 5:30 a.m., right below its “twin” star Castor. Read more about Pollux at https://goo.gl/cL5t9p.
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.
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