Almach (Gamma Andromedae)   HOME INDEX BACK NEXT

Double star in Andromeda

Star hop chart

Almach is a colorful double star, with a bright yellow primary and a blue secondary component. Both of these stars are much larger and brighter than the Sun. The yellow star is a giant star 2000 times more luminous and 80 larger in diameter than our Sun.

The blue star itself is a close double, but its two components are very close (averaging 0.3 arcseconds as they orbit every 63 years). It would take a large telescope and excellent seeing conditions to split the two components of the blue star.

Magnitudes 2.2, 5.0
Separation 9.8"
Distance (light yrs) 390
Right Ascension 2:03.9
Declination +42 20
Field of View 28' x 18'

Image details:  Five exposures each of 1/80, 1/20, 1/5, 1, and 4 seconds at ISO 12800, taken with a Canon T6i camera through a Meade 14” LX850 telescope at f/8. 

November 2017