Albireo , β Cygnus , Beta Cygnus , β Cyg - the fifth brightest star in the constellation Cygnus . It is a binary system , clearly distinguishable even in a small telescope :
- Albireo A , a visible magnitude of 3.4 m , an orange giant of spectral class K.
- Albireo B , apparent magnitude 5.1 m , blue star of the main sequence of spectral class B9.
| Albireo | |||
|---|---|---|---|
| Star | |||
 Albireo is located in the lower right corner. The cross-shaped figure is the so-called Northern Cross . The blue line shows the borders of the constellation Cygnus | |||
| Observational data ( Age J2000.0 ) | |||
| Right ascension | |||
| Declination | |||
| Distance | 385 St. years (118 pc ) | ||
| Visible magnitude ( V ) | 3.08 / 5.10 | ||
| Constellation | |||
| Astrometry | |||
| Radial velocity ( R v ) | −24.0 km / s | ||
| Own movement (μ) | RA: −7.09 mas per year Dec: −5.667 mas per year | ||
| Parallax (π) | 8.46 ± 0.58 mas | ||
| Absolute magnitude (V) | −2.28 / -0.26 | ||
| Characteristics | |||
| Spectral class | K3 II / B8 V | ||
| Color Index ( B - V ) | 1.13 | ||
| Color Index ( U - B ) | 0.62 | ||
| physical characteristics | |||
| Weight | 5 / 3.3 M ☉ | ||
| Radius | 69 - 109 / 3.1 R ☉ | ||
| Temperature | 4,300 / 12,100 K | ||
| Luminosity | 950/190 L ☉ | ||
| |||
| Database Information | |||
| SIMBAD | data | ||
Due to the large distance between the components (34 arc seconds ), it has long been assumed that Albireo is an optical binary , that is, two stars at different distances, projecting onto close points of the starry sky. It is now known that Albireo A and B form a real binary system with a circulation period of about 100,000 years.
Albireo A itself is a close binary system.
Since Albireo is located in the area of the “head” of the Swan, it is sometimes called in English “beak star” (“beak star”). Together with the stars Deneb , δ Cygnus and ε Cygnus, Albireo forms the “ Northern Cross ”.
In Arabic texts, the star was called al-Minhar al-Dajajah , "the beak of the chicken." The modern name of the star is the result of a series of erroneous readings and erroneous translations. The Greek name for the constellation Cygnus is Bird, Ορνιθος, which the Arabs wrote as Urnis. When translating Arabic texts into Latin, this word was mistaken for the name of the plant (possibly iris ), and translated as ab ireo (with the Latin article ab ). Finally, in successive rewritings of the text, the word was mistaken for a typo and was mistakenly reconstructed with the Arabic article as follows: al-bireo .
In Culture
Albireo is mentioned in the Andromeda Nebula novel as "the beauty of a double star", located at the same distance from Earth as Deneb
Notes
- ↑ 1 2 3 4 Leeuwen F. v. Validation of the new Hipparcos reduction // Astron. Astrophys. - EDP Sciences , 2007. - Vol. 474, Iss. 2. - P. 653–664. - ISSN 0004-6361 ; 0365-0138 ; 1432-0746 ; 1286-4846 - doi: 10.1051 / 0004-6361: 20078357 - arXiv: 0708.1752