Beta Lyrae
 Location of β Lyrae in Lyra |
|
| Observation data Epoch J2000.0 Equinox J2000.0 |
|
|---|---|
| Constellation | Lyra |
| Right ascension | 18h 50m 04.79525s |
| Declination | +33° 21′ 45.6100″ |
| Apparent magnitude (V) | 3.52(3.25 – 4.36) |
| Characteristics | |
| Spectral type | B7Ve + B |
| U−B color index | −0.56 |
| B−V color index | +0.00 |
| Variable type | β Lyr |
| Astrometry | |
| Radial velocity (Rv) | −19.2 km/s |
| Proper motion (μ) |
RA: 1.90 mas/yr Dec.: −3.53 mas/yr |
| Parallax (π) | 3.39 ± 0.17mas |
| Distance | 960 ± 50 ly (290 ± 10 pc) |
| Absolute magnitude (MV) | −3.91 |
| Absolute bolometric magnitude (Mbol) |
–6.3 ± 0.2 / –4.7 ± 0.1 |
| Orbit | |
| Companion | Beta Lyrae B |
| Period (P) | 12.9414 days |
| Semi-major axis (a) | 0.865 ± 0.048" |
| Eccentricity (e) | 0 |
| Inclination (i) | 92.25 ± 0.82° |
| Longitude of the node (Ω) | 254.39 ± 0.83° |
| Details | |
| β Lyr A | |
| Mass | 13.16 ± 0.3 M☉ |
| Radius | 6.0 ± 0.2 R☉ |
| Luminosity | 26,300 L☉ |
| Surface gravity (log g) | 4.0 ± 0.1 cgs |
| Temperature | 30,000 ± 2,000 K |
| β Lyr B | |
| Mass | 2.97 ± 0.2 M☉ |
| Radius | 15.2 ± 0.2 R☉ |
| Luminosity | 6,500 L☉ |
| Surface gravity (log g) | 2.5 ± 0.1 cgs |
| Temperature | 13,300 K |
| Age | 23 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Beta Lyrae (β Lyrae, abbreviated Beta Lyr, β Lyr), also named Sheliak, is a binary star system approximately 960 light-years (290 parsecs) from the Sun in the constellation of Lyra.
β Lyrae (Latinised to Beta Lyrae) is the system's Bayer designation, established by Johann Bayer in his Uranometria of 1603. It also bears the Flamsteed designation 10 Lyrae.
Beta Lyrae bore the traditional name Sheliak (occasionally Shelyak or Shiliak), derived from the Arabic الشلياق šiliyāq or Al Shilyāk, one of the names of the constellation of Lyra in Islamic astronomy. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN approved the name Sheliak for this star on 21 August 2016 and it is now so entered in the IAU Catalog of Star Names.
In Chinese astronomy, Tsan Tae (漸台 (Jiāntāi), meaning Clepsydra Terrace, refers to an asterism consisting of this star, Delta2 Lyrae, Gamma Lyrae and Iota Lyrae. Consequently, Beta Lyrae itself is known as 漸台二 (Jiāntāièr, English: the Second Star of Clepsydra Terrace.)
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