Almach – The Jewel of Andromeda

[Mr Spock]

Andromeda was a princess, the daughter of Cepheus and Cassiopeia. She was chained to a rock to be consumed by Cetus but was rescued by Perseus. The subject of many a movie, and the animation of Ray Harryhausen.

For many, the galaxy M31 is the most spectacular sight in Andromeda, but for double star observers, Almach, or γ Andromedae, is the real jewel in Andromeda’s crown.

Almach was discovered to be double in 1778 by Johann Tobias Meyer. It appears in the catalogue of Friedrich Georg Wilhelm von Struve as Σ205. It rivals Albireo as the most spectacular sight in the northern skies, some even consider it superior.

With a yellow magnitude 2.31 primary and blue magnitude 5.02 secondary and a separation of 9.4”, it’s an easy target for small telescopes – try around x50 to start. 

It doesn’t end there. The secondary γ ² is also double, but with a separation of 0.3” it is beyond all but the largest scopes. One of those is also a spectroscopic binary, so, quite a complicated quadruple system. γ ² has an orbital period of 63.7 years with an actual separation of 33 AUs, and the spectroscopic binary 2.7 days.

Almach is around 430 light years distant, and the main pair have an orbital period of 4700 years. The main component is a type K giant star; the secondary consists of a type A main sequence star and a spectroscopic binary of two type B main sequence stars.

If you get clear skies, Almach is very prominent right now. So go out and give it a look. I promise you won’t be disappointed.
 

[MarkRadice]

Seconded! I always check my finder and Sky Safari alignment on beautiful Almach before exploring the autumn skies. A lovely sight isn't it?

[MylesGibson]

This is also one that I observe regularly. Fantastic must-see for sure! I think it's definitely a rival to Albireo, although not too sure about better......

[Pixies]

Found this for the first tie this year. Not sure why I had missed it before.

I find it surpasses Albireo, but not sure why. Perhaps because it's a little tighter which might make the colour contrast stand out more.

Would be interesting to compare the two with images taken with similar equipment and similar technique.

[Captain Scarlet]

I too am in the camp which considers Almach superior to Albireo though they both are beautiful. Especially too considering that Almach is a true gravitationally-bound system, whereas Albireo is an optical.

[RobertI]

Lovely overview of Almach - it is indeed a beautiful sight.

[Spile]

I targeted Almach before Alberio when I got my telescope and I found it stunning. The closer pair does it for me as well.

[MylesGibson]

All of these in the Almach camp means it must be time for a re-viewing of both! 

[Mr Spock]

Both are on view at the  moment. Now is the time!

[Ian McCallum]

1 hour ago, Mr Spock said:

Both are on view at the  moment. Now is the time!

Except it's been raining heavy here and there are still a lot of heavy clouds about!☹️

[MylesGibson]

14 hours ago, Mr Spock said:

Both are on view at the  moment. Now is the time!

Weather needs to change first! Lol