Images Credit & Copyright: Me.
What do you do when the Moon is near full and you don’t want to observe it? Look at some star systems. It’s true that even star observing benefits from dark skies but you can still have some fun and get some quality observing done on the local points of light in our galaxy in light polluted or Moon lit skies.
Let’s take a look at two with great color contrast that you can see on any given late summer or early fall evening.
The above image is a beautiful double star system in the constellation of Cygnus the Swan named Albireo (Beta Cygni). You will often hear this star being called the Beak Star, as it’s where the head of the swan would be. It’s also one of the main stars in the Northern Cross asterism. If it’s been a while, an asterism is an easily recognizable pattern of stars that’s not one of the recognized 88 constellations. The most famous of these is probably the Big Dipper.
The Albireo system resides 430 light years away and it’s composed of two main stars; Albireo A (red) and Albireo B (blue) and the two are stunning in almost any sized telescope. They’re separated by 34.3” arcseconds on the night sky and take about 10,000 years to orbit one another. That’s if they’re a true binary and not just an optical pair which means they’re just lined up as we see them. Astronomers still aren’t certain which one it is yet.
They’re a mainly summer object but they can still easily be seen in September’s skies in the northern hemisphere. It’s been discovered that the red star has another smaller star orbiting it though too small and close to really make out in amateur telescopes. Thus, the three star Albireo-system is cataloged as; Albireo Aa (red star), Albireo Ac (red star’s smaller partner) and Albireo B (blue star).
HOW TO LOCATE:
RA 19h 30m 43.286s / DEC +27° 57′ 34.84″
The second team of stars in this post is going to be another red and blue pair, this time 350 light years away at the left foot of Andromeda (maybe she wears toe rings) named Almach (Gamma Andromedae). This red and blue pair is visually much tighter than Albireo with a separation of only 10” arcseconds but it’s just as brilliant when observed through a telescope.
This pair also hides a surprise as it’s been discovered that the blue star has two smaller companions orbiting each other while they orbit it but they are too small to split in amateur scopes. You can have fun with this system well into the New Year as Andromeda is rising as the Sun sets in the northern hemisphere now.
HOW TO LOCATE
RA 02h 03m 53.9531s / DEC +42° 19′ 47.009″