KW Sagittarii
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 17h 52m 00.72695s |
| Declination | −28° 01′ 20.5557″ |
| Apparent magnitude (V) | 11.0 |
| Characteristics | |
| Evolutionary stage | Red supergiant or hypergiant |
| Spectral type | M1.5Iab (M0I - M4Ia) |
| Apparent magnitude (K) | 1.43 |
| U−B color index | 3.21 |
| B−V color index | 2.47 |
| V−R color index | 2.58 |
| J−K color index | 1.56 |
| Variable type | SRc |
| Astrometry | |
| Radial velocity (Rv) | −7.40 km/s |
| Proper motion (μ) | RA: +0.843 mas/yr Dec.: −0.946 mas/yr |
| Parallax (π) | 0.4355±0.0726 mas |
| Distance | 7,890 ly (2,420 pc) |
| Absolute magnitude (MV) | −7.7 |
| Details | |
| Mass | 20 (or 40) M☉ |
| Radius | 1,009±142 R☉ |
| Luminosity (bolometric) | 175,000±52,000 L☉ |
| Surface gravity (log g) | 0.0 cgs |
| Temperature | 3,720±183 K |
| Other designations | |
| KW Sgr, AAVSO 1745-28, CD−27°12032, HD 316496, HIP 87433, Gaia DR2 4063462206570029312, Gaia DR3 4063462206570029312 | |
| Database references | |
| SIMBAD | data |
KW Sagittarii is a red supergiant or hypergiant star, located approximately 2,420 parsecs (7,900 light-years) away from the Sun in the direction of the constellation Sagittarius. It is one of the largest known stars, with a diameter about 1,000 times larger than the Sun. If placed at the center of the Solar System, the star's surface would engulf Mars, coming close to Jupiter's orbit.