Beta Trianguli
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Triangulum |
| Right ascension | 02h 09m 32.62712s |
| Declination | +34° 59′ 14.2694″ |
| Apparent magnitude (V) | +3.00 (3.44 + 4.19) |
| Characteristics | |
| Spectral type | A8III / A3III |
| U−B color index | +0.11 |
| B−V color index | +0.21 / 0.07 |
| Astrometry | |
| Radial velocity (Rv) | +9.9 km/s |
| Proper motion (μ) | RA: 149.16 mas/yr Dec.: –39.10 mas/yr |
| Parallax (π) | 23.169±0.434 mas |
| Distance | 141 ± 3 ly (43.2 ± 0.8 pc) |
| Absolute magnitude (MV) | −0.136 (0.305 + 0.1055) |
| Orbit | |
| Period (P) | 31.3884 d |
| Semi-major axis (a) | 0.330±0.005 AU |
| Eccentricity (e) | 0.53 |
| Periastron epoch (T) | 2432004.255 JD |
| Argument of periastron (ω) (secondary) | 318.4° |
| Semi-amplitude (K1) (primary) | 33.3 km/s |
| Semi-amplitude (K2) (secondary) | 69.2 km/s |
| Details | |
| A | |
| Mass | 3.52±0.27 M☉ |
| Radius | 4.38 R☉ |
| Luminosity | 60.3+15.6 −12.4 L☉ |
| Surface gravity (log g) | 3.70 cgs |
| Temperature | 7,683 K |
| Rotational velocity (v sin i) | 70 km/s |
| Age | 0.40+0.23 −0.15 Gyr |
| B | |
| Mass | 1.37±0.09 M☉ |
| Radius | 2.44 R☉ |
| Luminosity | 31.6+3.9 −3.4 L☉ |
| Temperature | 8,759 K |
| Age | 0.45+0.12 −0.09 Gyr |
| Other designations | |
| Alaybasan, β Tri, 4 Tri, BD+34°381, FK5 75, HD 13161, HIP 10064, HR 622, SAO 55306 | |
| Database references | |
| SIMBAD | data |
Beta Trianguli, formally named Alaybasan (for component A), is a binary star system in the constellation Triangulum, located about 127 light years from Earth. Although it is only a third-magnitude star, it is the brightest star in the constellation Triangulum.