Related Content

More Like This

Show all results sharing these subjects:

  • Science and technology
  • Astronomy and Cosmology

GO

Show Summary Details

Overview

Castor


Quick Reference

The star Alpha Geminorum, which appears to the naked eye of magnitude 1.6 but which is actually a complex multiple star. A small telescope divides Castor into two stars of magnitudes 1.9 and 2.9, both A-type dwarfs, which orbit each other with a period of about 450 years. Each is a spectroscopic binary. There is a third star, known as Castor C or YY Geminorum, an eclipsing pair of M1 dwarfs that ranges from magnitude 9.2 to 9.6 in a period of 0.8 days. The six-star system lies 51 l.y. away.


Reference entries