01/23/2012 -Ephemeris – The constellation Gemini the twins
Ephemeris for Monday, January 23rd. The sun will rise at 8:10. It’ll be up for 9 hours and 27 minutes, setting at 5:38. The moon is new today, and won’t be visible.
The constellation of Gemini the twins appears high in the southeast. It appears to the upper left of Orion and the stars that portray his club raised high. Gemini’s two brightest stars are the namesakes of the twins. Castor above and Pollux below. From them there are two lines of stars that form the silhouette of the lads heading to the lower right. In Greek mythology these twins each had a different father, not unheard of in medical history, with Pollux being fathered by the god Zeus and thus immortal. Castor was not. But the brothers were inseparable, so when Castor was killed in the search for the golden fleece Pollux begged his father to let him die too and join his brother. His wish was granted and his devotion was so great that they were placed in the sky where we see them today.
* Times, as always are for the Traverse City/Interlochen area of Michigan.
Addendum
Gemini and Orion. Created using Cartes du Ciel
Bob Moler's Ephemeris Blog 
The reason for the name Castor is unclear, although there appears no specific connection with the beaver, which is what the word means in Latin. It also is not clear why this star holds the appellation of “Alpha,” because it is clearly secondary in brightness to Pollux, which is called “Beta Geminorum.” In any event there is much mythology associated with the two stars, typically only in conjunction with each other, and they are usually considered to be twins. In Greek mythology Pollux is immortal, the son of Zeus, and Castor is mortal, the son of King Tyndareus of Sparta. Thus they were really half-brothers rather than true twins, with a common mother in Queen Leda. Their conception and birth, however, was a complicated and unlikely affair, with their mother succumbing to both Zeus (disguised as a swan) and King Tyndareus on the same night, with the resulting birth not only of Castor and Pollux, but of their sister Helen of Troy. Castor and Pollux later were among the argonauts who sailed with Jason in search of the Golden Fleece, and due to their mutual devotion, Zeus placed them both in the heavens on their death, so that they could remain together forever.