Beta Arae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ara |
| Right ascension | 17h 25m 17.989s |
| Declination | −55° 31′ 47.57″ |
| Apparent magnitude (V) | 2.84 |
| Characteristics | |
| Evolutionary stage | Red supergiant |
| Spectral type | K0/1Ib |
| U−B color index | +1.56 |
| B−V color index | +1.46 |
| Astrometry | |
| Radial velocity (Rv) | −0.3±0.2 km/s |
| Proper motion (μ) | RA: −8.51 mas/yr Dec.: −25.24 mas/yr |
| Parallax (π) | 4.5601±0.2077 mas |
| Distance | 714+39 −34 ly (218.8+12.0 −10.4 pc) |
| Absolute magnitude (MV) | −3.494 |
| Details | |
| Mass | 5.89±0.07 or 7.89±0.4 M☉ |
| Radius | 141.4±6.6 R☉ |
| Luminosity | 5,774±535 L☉ |
| Surface gravity (log g) | 0.97±0.06 cgs |
| Temperature | 4,232±17 K |
| Metallicity [Fe/H] | 0.5±0.1 dex |
| Rotational velocity (v sin i) | 5.4±1.0 km/s |
| Age | 50.1±4.4 Myr |
| Other designations | |
| CPD−55°8100, FK5 645, GC 23515, HD 157244, HIP 85258, HR 6461, SAO 244725, PPM 345989 | |
| Database references | |
| SIMBAD | data |
Beta Arae is the brightest star in the constellation of Ara. This is a very luminous, relatively young red supergiant with an apparent visual magnitude of 2.84 and an absolute magnitude of −3.494. Its name is a Bayer designation that is Latinized from β Arae, and abbreviated Beta Ara or β Ara. Based on a photogeometric estimation method, it is 710 light-years away, a distance of which interstellar extinction in the line of sight reduces its apparent magnitude by 0.193 magnitudes.