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.
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.
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.
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.