Thursday, April 23, 2009

The Ellensburg sky for the week of 4/25/09

Saturday: Scientists have discovered a 1980s-type pop song that they think is the first documentation of sunspots. It says, in part, “There was a little black spot in 1610. Ain’t seen nothing like it since who knows when”. Apparently the band The Police studied historical documents in astronomy before writing the song “King of Pain”. Galileo first observed sunspots in 1610 and wrote about it in 1612. This discovery was another knock against the theory that the heavens are unchanging. Sunspots come and go on a roughly eleven year cycle of maximums and minimums. We are currently in a sunspot minimum. Go to for more information about the Sun.

Sunday: Mercury and the Pleiades are right below the Moon at 9 p.m. Mercury is the fairly bright point of light a half a fist held upright and at arm’s length above the west-northwest horizon. The open star cluster the Pleiades is between the two.

Monday: May’s “Hot Topic” for the International Year of Astronomy, appropriately named, is the Sun. Go to for more information.

Tuesday: Are you a henpecked husband? King Cepheus was. He was so captivated by his wife Cassiopeia’s beauty that he let her rule their home. You can tell who is boss by looking in the northern sky at 10 p.m. Cassiopeia is the prominent W-shaped grouping of stars two fists above the north horizon. Cepheus is the much dimmer house-shaped grouping of stars about a fist to the right of Cassiopeia.

Wednesday: Normally, the bright stars Pollux and Castor are considered the Gemini twins. But, tonight, you will be forgiven for considering the Moon, Pollux, and Castor the triplets. Triplets where one child looks much bigger than the others. At 10 p.m., Pollux is less than a fist above the Moon and Castor is a half a fist to the right of Pollux. Pollux is the brightest star in the nighttime sky which is known to have a planet orbiting it. This planet, known as Pollux b, is about twice the mass of Jupiter and orbits the same distance from Pollux as Mars does around our Sun. It is unlikely that this planet has life similar to life on Earth owing to its size and distance from Pollux. But, not impossible. More promising, Pollux may be orbited by smaller, more Earth-like planets.

Thursday: Hydra the sea serpent rears its ugly head in the southwest sky at 10 p.m. First find Procyon. This bright star is two and a half fists above the west-southwest horizon. Next, find Saturn and Regulus right next to each other, five fists above the southwest horizon. Now, draw an imaginary line between Procyon and Regulus. Just below the midway point of that line, you should see a clump of stars that make the shape of a crooked house. This is the head of Hydra.

Friday: Saturn is five fists above the south horizon at 10 p.m.

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

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