Thursday, November 19, 2015

The Ellensburg WA sky for the week of 11/21/15

Saturday: Do you want to learn more about what goes on at night in the natural world? You can at a free event called Nature of Night on the CWU campus, today from 10 a.m. to 3 p.m. Go to the Science Building, I-8 on the map found at The Center for Excellence in Science and Mathematics Education gets help from various community organizations to put on this event.

Sunday: Are you disappointed because you are not going anywhere for Thanksgiving? Why not take a (virtual) trip to outer space using Google’s new visualization tool called 100,000 Stars. It shows the stars in our neighborhood in a very good simulation of 3-D. The Sun is initially at the center. If you zoom in, you can click on neighboring stars and learn more about them. For more information and a link to the tool, go to

Monday: Lieutenant Worf, the Klingon Starfleet officer on Star Trek: The Next Generation, might say “Today is a good day to die.” But Deneb, the bright supergiant star in Cygnus the Swan would say “two million years from now is a good day to die.” This may seem like a long time. But, compared to most stars, two million years from now is as close as today. For example, the Sun will last about five billion years. Small stars known as red dwarfs may last trillions of years. Prepare your astronomically short good byes to Deneb tonight at 7 o’clock when it is six and half fists held upright and at arm’s length above the west horizon.

Tuesday: Are you thankful that you live in a solar system with multiple planets? You should be. A giant planet like Jupiter cleans up planetary debris that could have collided with Earth and hindered the formation of complex life. Any inhabitants of the planets orbiting Upsilon Andromedae are thankful for this, as well. Upsilon Andromedae, a star in the constellation Andromeda, was the first Sun-like star discovered to have multiple planets orbiting it. So far, all of its planets are giant planets like Jupiter. But, the system is likely to also contain smaller planets. The dim star, but certainly not its planets, is barely visible straight overhead at 9 p.m. Jupiter is much easier to see, but you have to wait until tomorrow morning to see it. It is four and a half fists above the south-southeast horizon at 6:30 a.m.

Wednesday: Venus, the brightest point of light in the sky, is three fists above due southeast at 6:30 a.m. Mar’s is a little more than a fist to the upper right of Venus. The bright star Spica is a little less than a fist below Venus.

Thursday: Some of us have a lot to be thankful for on Thanksgiving. But, probably not as much as Andromeda had to be thankful for. According to Greek mythology, the beautiful princess Andromeda was chained to a rock next to the ocean. Cetus the sea monster was about to devour her in order to punish her family. Her mother Queen Cassiopeia and her father King Cepheus didn’t know what to do. It seemed that all was lost. But, along came Andromeda’s boyfriend, the great warrior Perseus. Even though Perseus’ standing as the son of King Zeus and the slayer of Medusa was probably enough to win Andromeda under normal circumstances, Andromeda’s impending death-by-sea-monster was not a normal circumstance. So, Perseus drove his sword into the sea monster’s neck and killed it. This was the first time in recorded history that a set of parents actually welcomed an uninvited Thanksgiving visit from the boyfriend. Perseus is about five fists above the east-northeast horizon and Andromeda is about seven fists above the east horizon at 7 p.m.

Friday: Tonight is a good night to calibrate your fists. The general rule is that a fist held out at arm’s length subtends an angle of 10 degrees. At 6:00 p.m., the bright star Altair, in Aquila the eagle, is exactly 40 degrees above due southwest. Thus, it should be exactly four fists above the horizon. In 2006, Altair became the first main sequence star, aside from the Sun, to have its surface imaged directly. The main sequence is a range of temperatures and luminosities where stars spend most of their lives.

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

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