Thursday, June 23, 2011

The Ellensburg sky for the week of 6/25/11

Saturday: Don’t wait until the 4th of July to go to those wimpy firecracker shows. Find the hypergiant star Rho Cassiopeiae. Astronomers think that Rho Cassiopeiae will likely go supernova (explode) in the near future. Of course, for stars, near future might mean today. It might mean 20,000 years from now. Rho Cassiopeiae is in the constellation Cassiopeia the queen. At 11:00 tonight, Cassiopeia looks like the letter “W” about three fists held upright and at arm’s length above the northeast horizon. Rho Cassiopeiae is about a finger’s width to the right of the rightmost star in the “W”. Once you find it you’ll be thinking, “Big deal, I can hardly see it.” Although it is barely visible to the naked eye, it is actually very bright. It is the 20th most luminous star in the sky, a whopping 550,000 times more luminous than the Sun.

Sunday: Jupiter is about a half a fist to the lower right of the Moon at 4:30 a.m. They are low in the eastern sky just ahead of the soon to be rising Sun.

Monday: What you can’t see can’t hurt you… if it does not hit the Earth. An asteroid estimated to be 25-55 feet across will come within 8,000 miles of hitting the Earth this morning at 6:30 a.m. Pacific Daylight Time. This asteroid is too dim to be seen by the naked eye anywhere in the world but will be visible to people with moderate sized telescopes in the far Southern Hemisphere. If an asteroid this size exploded close to the ground due to heating by the atmosphere, it would cause significant damage. Go to for more information.

Tuesday: Mars is less than a half a fist to the lower left of the Moon at 4:30 a.m. You’ll have to look carefully to see Mars in the dawn sky.

Wednesday: The green ring forged for the Green Lantern by the Guardians of the Universe couldn’t save the movie from bad reviews. But the green rings found by NASA’s Spitzer Space Telescope are helping astronomers learn more about “O” type stars, the most massive stars known. Go to for an example of a highly rated green ring.

Thursday: The constellation Cepheus the king (husband of Cassiopeia the queen) is about four fists above the northeast horizon at 11 pm. Cepheus is about one and a half fists above Cassiopeia. Cepheus looks like a house on its side with the roof peak pointing towards the west. Cassiopeia and Cepheus revolve around the North Star every night like a happy couple going through life together.

Friday: At the beginning of the June, I wrote about Mizar. Now that it is the beginning of July, I need to warn you not to confuse Mizar with its rhyming brother Izar in the constellation Bootes. Izar is also a binary star with about the same apparent brightness. And both were featured in different episodes of Star Trek. Izar was featured in the Star Trek episode “Whom Gods Destroy” from the original series. It is the base of Fleet Captain Garth, a former big shot in the federation and one of Kirk’s heroes before he went insane. Garth kidnaps Kirk and Spock before eventually being out smarted. Mizar doesn’t play as big a role in its episode. It is the star of the home world of one of the alien species in The Next Generation episode “Allegiance”. Izar is one fist above the bright star Arcturus and seven fists above the south horizon at 10 p.m. Mizar is seven fists above the northwest horizon at this time.

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

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