Gamma1 Andromedae

For any size telescope

Gamma 1 And (Almaak or Almach, 57 And, Struve 205) is one of my all-time favorite multiple stars because it is enjoyable on so many levels. In small scopes or when the seeing is poor the main pair form a striking contrast in color. The 2.1 magnitude sunlike primary star is a deep golden yellow. The fainter 5th magnitude secondary is an equally deep sky blue. They lie a comfortable 9.6" apart.


The view of the main pair in a 6" at 270x. North is down and east is right.

In larger scopes and on nights of good seeing the fainter blue star splits into a nearly matched pair (5.0 + 6.3 magnitude). These stars orbit each other once every 61.1 years are are currently separated by a mere 0.45" in PA 103o. In 1983 they reached their maximum separation of 0.57". They are currently closing and will continue until 2012 when they will be separated only 0.02"! If you want to see this pair. The sooner the better.


The orbit of the close pair with the stars drawn at their current positions.  The secondary star (left) is currently moving toward the primary (right).