Thursday, September 25, 2014
The Ellensburg sky for the week of 9/27/14
Saturday: Saturn is about a finger-width to the upper left of the moon at 8 p.m., very low in the west-southwest sky. Viewers in Hawaii will get to see the moon pass between Saturn and the Earth at about this time. The blocking of one celestial object by another is called an occultation. The group that sang, “Burnin’ for You” is Blue Oyster Cult.
Sunday: Mnemonics are helpful for remembering astronomy facts. (Similarly, “Johnny Mnemonic”, the 1995 cyberpunk film, was helpful in getting Keanu Reeves’ career going.) After all, school children all around the country are learning the order of the planets by remembering, “My very excellent mother just served us nine….” Oops, I guess that one needs updating. Well, here’s one that will not need updating for nearly 100,000 years: the order of the stars in the Big Dipper. Because the nighttime stars are so far away from us, their actual motion through the sky, called their “proper motion” is not noticeable over even thousands of years. That is why the constellations have remained the same since ancient times. But two stars in the Big Dipper have a proper motion large enough such than in 100,000 years, the stars will no longer make a dipper shape. Until then, you can remember the names of the seven dipper stars in order from handle to cup by remembering this helpful advice for teens: “AM, ask mom. PM, dad”. The stars are Alkaid, Mizar, Alioth, Megrez, Phad, Merek, and Duhbe. The Big Dipper is one fist held upright and at arm’s length above the north horizon at 11 p.m.
Monday: To the people of Ancient Greece, the stars that are about five and a half fists above the east-northeast horizon at 10 p.m. were known as Cassiopeia and Andromeda, a mythological queen and her daughter. But not all cultures imagined the same pictures in the sky. To the people of Polynesia, the stars of Cassiopeia and Andromeda represented a dolphin, called Kwu. Cassiopeia formed its tail, the brightest stars of Andromeda formed its fins, and its fainter stars outlined the dolphin’s body.
Tuesday: Aldebaran, the bright orangish star in the constellation Taurus, is one fist above the east horizon at 11 p.m.
Wednesday: Can’t sleep? Get up early and watch the largest planet in the Solar System and the brightest star in the night sky rise at the same time: 2:18 a.m. By 3 a.m., Sirius will be a half a fist above the east-southeast horizon and Jupiter will be a half a fist above the east-northeast horizon. By 3:05 a.m., you may return to bed.
Thursday: The cloudy season is coming to Ellensburg. Don’t feel bad. According to astronomers from the European Southern Observatory, it is always cloudy season on HD 85512b, a newly discovered planet orbiting the star called… wait for it… wait for it… called HD 85512. These astronomers developed a method to estimate the cloud cover on planets orbiting distant stars. They think HD 85512b may be cloudy enough to have liquid water on its surface even though it is fairly close to its host star. While the presence of surface water does not guarantee finding life, it is a critical component. For more information, go to http://goo.gl/bGxMD
Friday: The constellation Orion is four fists above the south horizon at 6 a.m. The Orion is a cloud of gas and dust visible with binoculars about a half a fist below the “belt” of three stars. Are you are feeling especially attracted to the nebula? If so, that might be because astronomers found evidence of a black hole in the middle. They have not directly observed the back hole, which would be the closest known one to Earth at a distance of 1,300 light years. But the motion of stars in the region is consistent with them being near a black hole 100 times the mass of the Sun. For more information, go to http://goo.gl/AGjFf.
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.