Gemini the Twins


From ancient times, the two brightest stars in this constellation have been known as twins of one form or another. Castor and Pollux have been called twin peacocks by the Arabs, twin sprouting plants by the Egyptians, and twin deities by the Hindus. From classic times the groups of stars have been known as the twins Castor and Pollux, sons of Jupiter and Leda. Castor raised exceptional horses, and Pollux was a warrior. The two joined the Argonauts on their search for the golden fleece, and joined the Roman soldiers in battles. The twins were also favorites of sailors. The effect known as St. Elmo's fire (the electrical charges seen around ships riggings in storms) was known as Ledean lights.

For the Observer

Autumn and Winter Skies

Alpha Geminorum, Castor (07h35m +31°53) has a magnitude of 1.6 blue-white class A2 star about 46 light years away. It is actually a triple system and each of those is a spectroscopic binary. The three pairs are called Castor A,B and C. Castor A and its companion have a magnitude of 1.9 and is two blue white stars. Castor B is also two blue white stars that have a magnitude of 2.9. Castor C and its companion are yellow-orange dwarfs. Castor has a March 1st transit.

Beta Geminorum, Pollux(07h45m +28°02') has a magnitude of 1.2 and is a yellow giant class K2 star about 35 light years distant.

Delta Geminorum, Wasat (07h17m.1 +22°05') has a magnitude of 3.51 and is a class F0 star about 53 light years distant. The star is a binary with the companion being a small red dwarf class K6. Colors for the two are reported as orange and purple. To view the colors easier put the eyepiece slightly out of focus.

Epsilon Geminorum, Mebsuta (06h40m.8 +25°11') is a 2.9 magnitude class G8 yellow giant star about 1100 light years distant. It has a 9th magnitude companion which is an optical double.

Zeta Geminorum (07h01m.1 +20°39') is one of the brightest of the cepheid variables. It is a giant star with a 10.15 day period. The magnitude changes from 4.4 to 5.2. The star has two optical companions of magnitudes 8 and 11.

M35 (6h05m.7 +24°20) is a galactic cluster of magnitude 5.3. The cluster has about 120 stars brighter than magnitude 13. It is about 2800 light years distant.

NGC2420 (07h35m.4 +21°41') is an open cluster. It has about 30 stars between magnitudes 10 through 18.

Copyright © 1995 - 2003
Kathy Miles, Author, and Chuck Peters, Systems Administrator