Wednesday, April 14, 2010

The Ellensburg sky for the week of 4/17/10

Saturday: Mars is five fists held upright and at arm’s length above the southwest horizon at 10 p.m. Less than a pinky width below Mars is the Beehive Cluster, an open star cluster of about 50 stars, all about 570 light years from Earth. The Beehive Cluster is a great object to look at through binoculars because it is big, taking up as much space in the sky as nine full moons. For the next few nights, Mars is an excellent marker.
If you get up before sunrise or stay up very late any night this week, be on the lookout for meteors coming from nearly straight overhead near dawn. The Lyrid meteor shower is active this week.

Sunday: 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 4:30 in the afternoon today. Spica, the brightest star in the constellation, rises at 7:30. By 9 p.m., Spica is a fist and a half above the southeast horizon. The northern section of Virgo will be marked by the planet Saturn for the next few months. Saturn is three and a half fists above the southeast horizon at 9 p.m.

Monday: How many of you know your 12 nearest neighbors? I thought so. Why don’t you go out and meet them right now. I’ll wait. Yes, of course bring them cookies. No, not those stale ones you hate.
Are you back? That means you obviously didn’t meet your 12 nearest stellar neighbors. Including the Sun, there are 12 stars within 10 light years of Earth. The most well known are the Sun (obviously); Proxima Centauri, the nearest star other than the Sun; Alpha Centauri, a bright binary star visible from the tropics and the Southern Hemisphere; and Sirius, the brightest star in the nighttime sky. Sirius is the largest and most luminous star in our neighborhood. It is one and a half fists above the southwest horizon at 9 p.m.

Tuesday: The Lyrid meteor shower peaks over the next two nights. 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 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. For most of the next two nights, the nearly first quarter Moon will be below the horizon meaning the sky will be dark enough to see dim meteors. This shower produces about 15 meteors, tiny rocks that hit the Earth and burn up in the atmosphere, every hour during the peak. 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.

Wednesday: Vega is two fists above the northeast horizon at 11 p.m.

Thursday: This month, Astronomers Without Borders is organizing “30 Nights of Star Peace” to promote staring the night sky across national borders, one section of the world at a time. For the next three nights (4/22-4/24), 108 to 144 degrees west longitude is celebrating Star Peace. Ellensburg is 120 degrees west longitude. If the only thing you do is look up at the night sky and spot Mars six fists above the southwest horizon at 9 p.m., please recognize that some of your neighbors in Canada and Mexico are doing the same thing. Go to for more information.

Friday: Jupiter is just creeping out of the glare of the rising Sun. It is about a half a fist above the east horizon at 5:15 a.m.

The positional information in this column about stars and planets is typically accurate for the entire week.

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