Almach (Gamma Andromedae) -- Multiple Star in Andromeda
Almach a Quadruple Star System
Gamma Andromedae (Almach) is an attractive double star in small telescopes. The
yellowish primary and bluish secondary stars complement each other nicely in the
eyepiece. I believe it is one of the nicest double-stars in the heavens.
The Almach Star System is far more complicated than the two stars that appear in my
eyepiece. The blue star is really a triplet system with a close companion that has an
extreme elongated orbit. This causes the separation of the two stars to vary between
0.2 to 0.5 arcseconds. This puts it out-of-range of most amateur telescopes (well
below the resolution of my 6-inch refractor). In addition, a third companion star exists
that is a spectroscopic binary (a star that cannot be separated visually by any
Almach provides a pleasing visual experience and at the same time challenges the
imagination to grasp the existence of its real 4-star system.