Wednesday, April 18, 2018

The Ellensburg WA sky for the week of 4/21/18

Saturday: Remember the old saying: April showers bring… meteors. The Lyrid meteor shower peaks tonight through tomorrow morning. The meteors appear to come from a point to the right of the bright bluish star Vega in the constellation Lyra the lyre. This point is about three fists held upright and at arm’s length above the east-northeast horizon at midnight tonight and close to straight overhead near dawn. The best time to look is just before dawn since that is when the radiant, or point from which the meteors appear to come, is high in the sky. This year, the Moon is in the first quarter phase so it will not be providing much light to obscure the meteors during the prime viewing time after midnight. Typically, this is one of the least interesting major meteor showers of the year. However, it is also one of the most unpredictable. As recently as 1982, there were 90 meteors visible during a single hour. In addition, the Lyrid meteor shower has historical interest because it was one of the first ones observed. Chinese records say “stars fell like rain” in the shower of 687 B.C. As your Mother might say, dress warm and sit in a comfortable chair for maximum enjoyment. Meteors are tiny rocks that hit the Earth and burn up in the atmosphere. For more information, go to http://earthsky.org/?p=158735. 

Sunday: Every night is a Girls Night Out this week as Venus, the goddess of love, hangs out with the Seven Sisters all week at this time. The Seven Sisters, also known as the Pleiades is an open cluster of about 1,000 stars that are all about 440 light years away. At 9 p.m., Venus is a half fist above the west-northwest horizon. Venus will move up toward the Pleaides throughout the week, passing closest on Wednesday. 

Monday: The nighttime stars take little more than an instant to rise. The Moon takers about two minutes to rise. That’s absolutely speedy compared to the constellation Virgo, which takes four hours to rise. The first star in Virgo rises at 4:00 in the afternoon. Spica, the brightest star in the constellation, rises at 7:00. By 9 p.m., Spica is one and a half fists above the southeast horizon. By 10 p.m., Jupiter, which has nothing to do with Spica or Virgo, is a half fist above the southeast horizon. 

Tuesday: Regulus is a half a fist to then upper right of the Moon at 9 p.m. They are five and a half fists above due south. 

Wednesday: Do people think you have a magnetic personality? The star Cor Caroli understands how you feel. Cor Caroli has one of the strongest magnetic fields among main sequence stars similar to our Sun. This strong magnetic field is thought to produce large sunspots that cause the brightness of Cor Caroli to vary. Cor Caroli is nearly straight overhead at midnight. 

Thursday: At 5:00 a.m., Saturn is two fists above the south horizon. Mars is about a fist to the lower left, about one and a half fists above the south-southeast horizon. 

Friday:  Sometimes you get to your car and realize that you are missing your keys or your sunglasses. The asteroid/dwarf planet Ceres is missing craters. Astronomers thought there would be many large, old craters marking the surface of Ceres. Instead, close-up images from NASA’s Dawn mission shows that Ceres is covered with numerous small, young craters. Possible explanations include the relatively soft icy surface smoothing out over time or that eruptions from ice volcanoes, called cryovolcanoes, buried the older craters. Ceres is visible in small telescopes or even 10x50 binoculars. Read more about how to find it at https://goo.gl/5X47iBAt 11 p.m., it is four and a half fists above the west-southwest horizon. 

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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