Epsilon Sagittarii
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 18h 24m 10.31840s |
| Declination | −34° 23′ 04.6193″ |
| Apparent magnitude (V) | +1.85 |
| Characteristics | |
| Evolutionary stage | Post-mass transfer |
| Spectral type | B9IVp |
| U−B color index | +0.13 |
| B−V color index | –0.03 |
| Astrometry | |
| Radial velocity (Rv) | −15 km/s |
| Proper motion (μ) | RA: −39.42 mas/yr Dec.: −124.20 mas/yr |
| Parallax (π) | 22.76±0.24 mas |
| Distance | 143 ± 2 ly (43.9 ± 0.5 pc) |
| Absolute magnitude (MV) | −1.41 |
| Details | |
| ε Sgr A | |
| Mass | 3.80 M☉ |
| Radius | 8.80 (equatorial) 6.01 (polar) R☉ |
| Luminosity | 497 L☉ |
| Surface gravity (log g) | 3.46 (polar) 2.00 (equatorial) cgs |
| Temperature | 11,720 (polar) 7,433 (equatorial) K |
| Rotation | 1.61 days |
| Rotational velocity (v sin i) | 236 km/s |
| Age | 232 Myr |
| ε Sgr B | |
| Mass | 0.95 M☉ |
| Radius | 0.93 R☉ |
| Luminosity | 0.891 L☉ |
| Temperature | 5,808 K |
| Other designations | |
| Kaus Australis, ε Sagittarii, ε Sgr, Epsilon Sgr, 20 Sagittarii, CCDM J18242-3423A, FK5 689, GC 25100, HD 169022, HIP 90185, HR 6879, IDS 18175-3427 A, PPM 297655, SAO 210091, WDS J18242-3423A | |
| Database references | |
| SIMBAD | data |
Epsilon Sagittarii (Latinised from ε Sagittarii, abbreviated Epsilon Sgr, ε Sgr), formally named Kaus Australis /ˈkɔːs ɔːˈstreɪlɪs/, is a binary star system in the southern zodiac constellation of Sagittarius. The apparent visual magnitude of +1.85 makes it the brightest object in Sagittarius. Based upon parallax measurements, this star is around 143 light-years (44 parsecs) from the Sun.