By Lee Dyson

Published: Thursday, 29 July 2021 at 12:00 am


Albireo is a double star 415 lightyears away and the second brightest star in the constellation Cygnus, the Swan.

Albireo is located at the end of the Swan’s ‘neck’ and can be found at the opposite end of the constellation to Deneb, which is Cygnus’s brightest star.

It can also be found by locating the Summer Triangle asterism (one of our favourite summer constellations and asterisms), as it lies within the triangle’s boundary.

"Albireo
Albireo in Cygnus by Danny Lee, Kent, UK. Equipment: Skywatcher 150P, EQ5 Pro mount, Nikon D40 at prime focus.

When observed through a telescope, Albireo A, the primary star, is a golden yellow colour shining mag. +3.1.
Albireo B, however, is a much cooler blue colour shining mag. +5.1

Albireo A is an orange giant about 5 times as massive as the Sun, while Albireo B is actually a much hotter and smaller star about 3 times the mass of the Sun.

"A
A selection of Double Stars by Sam Boyer, Wakefield, UK. Equipment: Skywatcher 200P, Phillips SPC900NC

There remains some debate as to whether or not Albireo is a binary star system (i.e. two stars gravitationally bound), or whether it’s simply two stars that appear to be near one another from our perspective on Earth.

Sky & Telescope Magazine have a fascinating article on this very topic that’s well worth a read.

Regardless of whether Albireo is a true binary system, the star is a beautiful sight to behold.

Albireo is well-placed for observing from June to September, and a view through a telescope will reveal the two stellar components quite spectacularly.

"Albireo
Albireo Kfir Simon, via Tivoli Astro Farm, Namibia, 20 June 2020. Equipment: FLI ProLine 16803 CCD camera, Phillip Keller 16-inch Hypergraph, ASA DDM 85 mount

See if you can spot their contrasting colours and revel in the satisfaction of having resolved this beautiful double star.

Below is a selection of images of Albireo captured by astrophotographers and BBC Sky at Night Magazine readers.

For astro imaging advice, read our beginner’s guide to astrophotography or discover our pick of the best astrophotography cameras.

And don’t forget to send us your images or share them with us via Facebook, Twitter and Instagram.

"Albireo
Albireo by Alexander Wilson, Aberdeen, UK. Equipment: Meade SC 8″, LXD75 mount, Meade Dsi 3 colour
"Albireo:
Albireo: A so beautiful double star in Cygnus by Houssem Ksontini, Tunisia. Equipment: Skywatcher 150/750, Neq3-2 AD motorised, Nikon D3000.
"Albireo
Albireo by Jaspal Chadha, London, UK. Equipment: Altair Astro RC 250, Focal Reducer, QHY9SM, Baader filters