Thursday, November 6, 2008

Halloween brings out the Demon Star

This may be an odd thing to post in my Blog, but the blog is about Astronomy and
this is astronomy related. I received it from my parents in newspaper form and
have typed it up to put it in the blog.

From AZ Republic Fri Oct 31, 2008 Section E page 1

Halloween Brings out the Demon Star
by John Stanley, Az Rep
(Only edits I may have made is abbreviations to shorten the article, and paragraph changes.)

The evening, as ghouls, goblins and other creatures of the night take to the streets to beg for sugary treats, take a moment to examine a real apparition: Algol, the Demon Star. The ancient Hebrews called it Rosh Ha Satan (Satan's Head) and its present name comes from the Arabic phrase Al Ra's al Ghul (the Demon's Head). Clearly, it has an unsavory reputation. But why? Every few days, for no aparent reason, Algol dims noticebly for several hours, then returns to its normal brightness. Ancient astronomers, for whom the immutability of the heaves was a given, found this disturbing. Algol is what astronomers call an eclipsing binary, which vary in brightness because a large, but dim, companion star periodically passes in front of the primary star, temporarily reducing its brightness. Look for Algol in the constellation Perseus, which is high in the northeast after sunset (Find a star chart at Make a mental note of Algol's brightness by comparing it with nearby stars. Then check it again during a minimum phase. The next one visible to observers in Arizona takes place from 8pm to 10pm on Nov 8th (that's this Saturday). Enjoy!

Terri, Events Coordinator
Phoenix Astronomical Society