A Halloween comet and a Ghoul Star
Print Me Email to FriendTonight's Sky for Wednesday, Oct 31 2007
Comet Holmes burst into visibility on October 24, becoming more than a million times brighter than it had been the day before. If you haven’t seen it yet … give it a try tonight! See it – on today’s sky chart – right next to the star Mirak in the constellation Perseus? You might be able to spot it from cities or the suburbs while trick or treating with the kids this Halloween.
How you can find the comet
Step 1. Face northeast. Which way is northeast? If you live in the northern hemisphere, the sun is setting in the southwest now. Watch the sunset, wait an hour until the sky gets dark, and stand with your back to the sunset direction. You are now facing northeast.
Step 2. Get oriented in the sky. Look first for a 3- or W-shaped pattern of stars. See it on the chart to the right? The W-shaped pattern is easy to spot. This is the constellation Cassiopeia. The constellation Perseus is below Cassiopeia in the northeast. Perseus is not as bright or prominent as Cassiopeia, but the comet now appears as one of the brightest stars in Perseus.
Step 3. Sweep for the comet. “Sweep” just means look steadily, systematically, sweeping your eyes from side to side at the place in the sky where you think the comet should be. Comet Holmes looks like a round, fuzzy ball in front of Perseus. It’s almost as bright as Mirfak, Perseus’ brightest star.
Remember, all stars look like pinpoints. Comet Holmes is a fuzzball.
By the way, on this Halloween night – as long as you’re looking in Perseus – also try looking at Beta Persei, otherwise known as Algol. This star’s proper name comes from the Arabic for “head of the ghoul,” or “head of the demon.” This star is known to vary in brightness over a regular time interval. The cycle lasts exactly 2 days, 20 hours and 49 minutes. All the while, the star remains visible to the eye. Algol’s brightness variations are not due to some special quality of a single star. In fact, this is a multiple star system, where one star regularly passes in front of another as seen from our earthly perspective.
Early stargazers had no way to know why Algol varied in brightness. But it’s likely that they did notice this star’s brightness change. Throughout parts of the ancient world, Algol was associated with demons or monsters. The Greeks and Romans identified the star with the Head of Medusa, a fearful monster with snakes in place of hair. The star has also been called The Ghoul Star.
Where is there an easy to read webpage that lets you know where all the planets are?
Thanx Zip