Alpha Trianguli Australis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Triangulum Australe |
| Right ascension | 16h 48m 39.89508s |
| Declination | −69° 01′ 39.7626″ |
| Apparent magnitude (V) | 1.91 |
| Characteristics | |
| Spectral type | K2Ib-IIa |
| U−B color index | +1.56 |
| B−V color index | +1.44 |
| Astrometry | |
| Radial velocity (Rv) | −3.3 km/s |
| Proper motion (μ) | RA: +17.99 mas/yr Dec.: −31.58 mas/yr |
| Parallax (π) | 8.35±0.15 mas |
| Distance | 391 ± 7 ly (120 ± 2 pc) |
| Absolute magnitude (MV) | −3.68 |
| Details | |
| Mass | 7 M☉ |
| Radius | 143 – 167 R☉ |
| Luminosity | 5,500 L☉ |
| Surface gravity (log g) | 1.5 cgs |
| Temperature | 4,150 K |
| Metallicity [Fe/H] | −0.06 dex |
| Age | 48 Myr |
| Other designations | |
| Atria, HR 6217, CD−68°2822, HD 150798, SAO 253700, FK5 625, GC 22558, HIP 82273 | |
| Database references | |
| SIMBAD | data |
Alpha Trianguli Australis (Latinised from α Trianguli Australis, abbreviated Alpha TrA, α TrA), officially named Atria /ˈeɪtriə/, is the brightest star in the southern constellation of Triangulum Australe, forming an apex of a triangle with Beta Trianguli Australis and Gamma Trianguli Australis that gives the constellation its name (Latin for southern triangle).