Demon star


The new moon was on the 25th, we still have beautiful dark skies for viewing. The Milky Way is beginning to move from the South to the Southwest as Earth's solar orbit changes into the autumn position. The other end still appears in the NE. Don't forget to look for the Taurid fireballs in the eastern evening sky.

Uranus is visible all night in the constellation Pisces, the fish which is along the ecliptic in the ESE. The ecliptic is the path of the Sun, moon and planets travel along in our sky. Currently it's about one-third of the way up. Try looking for it first with binoculars. It may appear light blue. 

This is also a great time to look for the Andromeda galaxy. Just look for Cassiopeia halfway up in the NE. The bottom star of the upper half of the "W" points to it. The galaxy is about a hand's width to the right and slightly lower. Use binoculars to find it, and then look with unaided vision. I guarantee you can see it on a clear dark night.

Now that Halloween is almost here, it's time to find the Demon star in the constellation Perseus. Its official name is Beta Perseis but is more commonly known as Algol which is Arabic for head of the ghoul or head of the demon. So, it's also called the Ghoul star.

Perseus is the constellation that sits below Cassiopeia. It's a large constellation in the shape of a man with a large triangular shape body. The brightest star Mirfak is on the lower left body where the leg begins. Algol is to the right of Mirfak anchoring the other side of the body.

Algol is a multiple star system of three stars, but only two are visible to us. The light changes each time one star passes in front of the other as they spin around each other. This causes it to vary in brightness over a regular time interval of 2 days, 20 hours and 49 minutes. It dims for 10 hours, and then gets bright again.

Because of this, Algol is called an eclipsing variable star. This dip in brightness can be seen with unaided vision. So, go out and look at it for several nights in a row to see the change in brightness.

It's assumed that since ancient stargazers didn't know why this happened, they thought that Algol was associated with demons or monsters. Greeks and Romans identified it with the head of Medusa, a monster with snakes in place of hair. Have a fun Halloween.

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