Take a long look at the most beautiful double star in the sky.
Albireo, also known as Beta Cygni, is at the top of the sky right now for people living north of the equator.
Credit: Henryk Kowalewski/Wikimedia Commons
- Albireo (Beta Cygni), located in the constellation Cygnus, has been highlighted as a prestigious double star system highly regarded by northern observers.
- The system consists of two components, Beta1 Cygni and Beta2 Cygni, which have apparent magnitudes of 3.2 and 5.1, respectively, separated by 34 arcseconds.
- A notable feature is the stunning chromatic contrast between its constituent stars, which are generally perceived as golden and sapphire blue despite individual perceptual variations.
- Physically, Beta1 Cygni displays a luminosity 795 times that of the Sun, and Beta2 Cygni is 110 times brighter, with the system located approximately 365 light years away; Its naming originates from a historical misinterpretation in the 1515 edition of Ptolemy’s *Almagest*.
Autumn in the Northern Hemisphere is a great time to hunt galaxias. You’ll find objects ranging from the amazing Andromeda Galaxy (M31) to Stephan’s Quintet (NGCs 7317, 7318A, 7318B, 7319, and 7320) to NGC 1. But except for a few like M31, most galaxies are faint and lack detail unless your telescope is large. Therefore, take occasional breaks during your observation session. Point a telescope of any size at the star Albireo (Beta Cygni), which marks the head of the Swan constellation. Most northern observers consider it to be the finest double star in the sky.
Astronomers have labeled Albireo’s two components (the stars that make up the binary star) Beta1 Cygni and Beta2 Signy. beta1Shines at magnitude 3.2, while Beta2 It is mild, coming in at 5.1 intensity. The separation between them is 34″, meaning even the smallest binoculars will successfully split them. But it’s not their magnitude or their separation that makes these stars a wonderful sight: it’s their colors.
Before I describe the colors of these two stars, let me point out that no two human eyes see exactly the same colors. That said, most observers “see” the beta1 As gold and beta2 As sapphire blue. But whether you actually see gold and blue, blue and white, yellow and green, or any other combination, it all adds up to an attractive sight in the eyepiece.
some more things
Both of Albireo’s brightest components (there are two other stars in the system, but they cannot be seen with amateur telescopes) are actually bright stars. beta1 is 795 times brighter than our Sun and beta2 Is 110 times brighter. This makes sense since Albireo is about 365 light years away.
Finally, although according to stellar nomenclature historian Richard Hinckley Allen the first two letters of Albireo are ”Al”, the star’s name is not Arabic, for example, Aldebaran (Alpha Tauri) and Algol (Beta Persei). The now universal title, he says, ”was apparently first applied to the star due to a misunderstanding about the words Irio in the description of the constellation in the 1515 edition. [Ptolemy’s] Almagest.”The Arabs called Albireo al minhar al dajjahChicken’s beak.
Whatever you call it, I hope your night clears up soon so you can go out, see, and enjoy the light of this stellar beauty.
