The Gemini constellation lay just above and left of Orion.
The two stars, Castor and Pollux are the heads of the twins in the zodiac constellation. Pollux is slightly brighter than Castor.
Although Castor has the designation "Alpha," it is actually the second brightest in the constellation after Pollux. 52 light-years from Earth, Castor appears as a magnitude 1.6 blue-white star to the unaided eye.
Beta Geminorum named for Pollux is, despite its designation, the brightest star in Gemini.
34 light-years from Earth, Pollux is a single yellow-orange giant star of magnitude 1.2. Castor is actually made up of six stars in 3 pairs.
Alhena(Gamma Geminorum)is a blue-white hued star of magnitude 1.9, 105 light-years from earth.
The Geminids are a prominent, bright meteor shower that peaks on December 13–14. It has a maximum rate of approximately 100 meteors per hour.
Right Ascension:7 hours
Declination: 20 degrees
Visible between latitudes +90 and -60 degrees
Best seen in February at 9:00 PM local time
Some stars in the constellation are: CASTOR (Alpha Geminorum) POLLUX (Beta Geminorum) ALHENA (Gamma Geminorum)
There are numerous double stars and binary systems in Gemini. Thus a lot of twins.
The main pair of Castor A and B is difficult to separate in small telescopes. Smaller telescopes require good optics, high power, steady skies and patience to resolve them.
The galactic star cluster M35 is near Castor's foot. M35 appears as a fuzzy spot in binoculars but is easily resolved in any astronomical telescope.
Southwest of M35 is the faint and distant star cluster NGC 2158. A compact cluster, not quite resolvable in a 6 inch telescope about 16,000 light years away.
NGC 2392-the Clown Face Nebula, which appears a blue-green in color is left of Pollux.
Gemini is also the constellation in which the dwarf planet Pluto was discovered in 1930 by Clyde Tombaugh.
According to Greek mythology the Gemini constellation's mother was Leda. Pollux was sired when Zeus (the Roman Jupiter) disguised as the swan Cygnus seduced Leda. Pollux thus was immortal, like his father.
Castor on the other hand was mortal. Tyndareus, who had relations with Leda the same night was his father.
Leda supposedly had quadruplets. Pollux and Helen, the famous Helen of Troy were fathered by Zeus; while Castor and Clytemnestra were the mortal offspring of Tyndareus.
Castor was a horseman. Pollux was a boxer. They sailed with Jason on board the Argo on his quest to recover the Golden Fleece.
Castor was killed in a battle with Idas, Pollux was so upset by the death of Castor that he asked Zeus to let him die too.
Zeus, touched by his son's devotion placed them both in the heavens as the constellation Gemini.Celestial Solar System › ZODIACS › Gemini