Wednesday, October 21, 2009

The Ellensburg sky for the week of 10/24/09

Saturday: “It’s a wonderful day in the neighborhood.” Constellations can be considered neighborhoods in the nighttime sky. But, the stars in those constellations are not necessarily neighbors in real life. For example, the bright stars in the constellation Cassiopeia range from 19 to over 10,000 light years away from Earth. One constellation that consists of real neighbors is Ursa Major. Or, more specifically, the Big Dipper. Five stars in the Big Dipper are all moving in the same direction in space, are about the same age and are all about 80 light years from Earth. “Please won’t you be my neighbor?” Skat, the third brightest star in the constellation Aquarius is a neighbor to these five Big Dipper stars, all of which are about 30 light years from each other. They are thought to have originated in the same nebula about 500 million years ago. Just like human children do, these child stars are slowly moving away from home. Skat is about three fists held upright and at arm’s length above due south at 10 p.m. The much brighter Fomalhaut is a fist and a half below Skat. And, it’s not fun being below Skat.

Sunday: Tonight’s first quarter moon is in the constellation Capricornus the sea goat.

Monday: Jupiter is about as finger’s width to the lower left of the Moon. They are two and a half fists above due south at 8 p.m.

Tuesday: The Stargate movies and TV shows have access to a portal to other planets. Harry Potter has access to a portal to the Chamber of Secrets. You have access to a Portal to the Universe. This portal, available not in Moaning Myrtle’s bathroom but on the web at, is a repository of up-to-date astronomy news, blogs, and podcasts.

Wednesday: Venus is one fist above the east-southeast horizon at 7 a.m. It is near the belly button of the maiden depicted in the constellation Virgo. Great. I hope this does start a new trend – tattooing a planet near your belly button.

Thursday: A few stars appear to be a color other than white to the naked eye. The reddish Betelgeuse in the constellation Orion and the bluish Vega in the constellation Lyra come to mind. But if you look with binoculars, the star Mu Cephei appears to be more vividly colored than either of these - a surprisingly deep red. This star, named the Garnet star by the astronomer William Herschel, is eight fists above the north horizon, very close to being straight overhead, at 8 p.m. It is a red supergiant star that varies in brightness by about a factor of five over a two-year period. If our Sun were replaced by Mu Cephei, it would fill up the solar system out to halfway between Jupiter and Saturn.

Friday: Finally, you don’t have to be an insomniac or work the late shift to see Mars before you go to bed! Mars is a half a fist above the east-northeast horizon at midnight.

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

No comments: