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[starz4me]

Hi, just wondering if anyone is setting up telescopes to check this out this week? Most reasonable date for Chicago area seems to be Sept 13, as it will be at its minimum at 10:41pm. it seemed interesting that it will go from its brightest to minimum in justv2 hours. Just curious!

[Centaur]

Sept 8, 2012 8:03:26 GMT -6 starz4me said:

Hi, just wondering if anyone is setting up telescopes to check this out this week? Most reasonable date for Chicago area seems to be Sept 13, as it will be at its minimum at 10:41pm. it seemed interesting that it will go from its brightest to minimum in justv2 hours. Just curious!

Welcome to the discussion group, starz4me.

Possibly your interest in Algol was piqued by a Space.com article which implied that this week is somehow special for viewing Algol. Actually, Algol is visible every night throughout the year for Chicagolanders, and appears near the zenith during mid-evenings in December. Tonight it will rise for observers at the Adler Planetarium at 19:14 CDT, transit the local north-south meridian less than 1° south of the zenith at 04:44, and then set during the daytime tomorrow at 14:14. These times will only vary by a minute or two throughout Chicagoland. These events will occur nearly four (3.93167) minutes earlier each day.

The cycle for Algol’s partial eclipses is 68:48:56.5 hrs (2.86732 days), with each eclipse lasting about 9:40 hrs. Due to the speed of light and the position of Earth in its orbit and the relative positions among the three stars within the Algol system, the occurrences can vary by a number of minutes from uncorrected predictions. Minimum brightness is expected on 2012 SEP 11 at 03:14 CDT (SEP 11.13472 CDT) according to the Sky & Telescope interactive table: www.skyandtelescope.com/observing/objects/variablestars/Minima_of_Algol.html . You can then add the cycle length for later predictions.

Enjoy the sight! A telescope is not necessary, since Algol is easily visible by naked eye in the magnitude range 2.12 to 3.40.

[starz4me]

Yes, I saw the post on Space.com. Thanks for the information!

[Paulie pchris00]

I have never observed a variable star, not even Algol. I couldn't even point out Algol without looking at a star chart. Some astronomer I am...

[Centaur]

Sept 10, 2012 20:23:29 GMT -6 Paulie pchris00 said:

I have never observed a variable star, not even Algol. I couldn't even point out Algol without looking at a star chart. Some astronomer I am...

Well, Paulie, Algol is the one to start with. It's easily visible by naked-eye and has a short and highly regular period. It's not variable in the usual sense, but involves a binary pair orbiting in a plane that nearly includes the Earth. When the darker star partially occults the brighter one, their combined light noticeably lessens from our point of view. There's much in the sky to appreciate without the need for a telescope. Let us know if you discover the wonder of the winking star Algol.