Some Bright Winter Double Stars
December 2005 :
The winter night sky, dominated by mighty Orion, is rich with deep-sky splendors. If you can brave the cold, you’ll be rewarded by some of the finest double and triple stars the night sky has to offer. I highly recommend you check out the following ten:
gamma Andromedae (Almach) magnitudes 2.3 and 5.1, separation 10.0 arcseconds. A stunning gold and blue pair. This is one of the most beautiful double stars in the entire night sky.
iota Cassiopeiae mags 4.7, 7.0, and 8.3, sep 2.5” and 7.3” Fine triple. A challenge for 3-inch scopes, because of the closeness of the mag 4.7 and 7.0 components.
epsilon Arietis mags 5.7 and 6.0, sep 1.4” Here’s a neat test object for a 3-inch scope, because its separation lies at the theoretical limit for such an instrument.
omicron2 Eridani mags 4.5 and 9.4, sep 83.4” A wide, unequal pair. The companion is one of the few white dwarf stars visible in small scopes. It’s orbited by an 11th magnitude red dwarf, some 9” away.
beta Orionis (Rigel) mags 0.1 and 6.7, sep 9.4” Small scope users will have a tough time glimpsing the companion, which hides in the glare of the brilliant primary.
theta1 Orionis mags 5.4, 6.6, 6.8, and 8.0v, sep 13.3”, 13.1” and 16.8” The “Trapezium,” located in the heart of the Orion Nebula (M42). This is easily the finest multiple star in the heavens. Two fainter Trapezium members can be seen in a 6-inch scope.
beta Monocerotis mags 4.5, 5.2, and 6.1, sep 7.3” and 10.0” We follow the finest multiple star the night sky has to offer with what many observers regard as the most striking triple. An incredible sight at 120X. All white.
h3945 Canis Majoris mags 4.8 and 6.8, sep 26.6” Here’s a gold and blue pair that rivals the muchcelebrated Albireo. Absolutely beautiful!
alpha Geminorum (Castor) mags 2.0 and 2.8, sep 4.4” A binary star that has been widening from a minimum separation of 1.8” in 1969. Now an easy sight in the smallest of scopes. Look for a 9th magnitude star 72.5” away. All three stars are spectroscopic binaries, making Castor a sextuple star!
k Puppis mags 4.5 and 4.6, sep 9.9” A beautiful twin system, both white.
