Westerlund 1 W26
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ara |
| Right ascension | 16h 47m 05.403s |
| Declination | −45° 50′ 36.76″ |
| Apparent magnitude (V) | 17.194 |
| Characteristics | |
| Spectral type | M0.5–M6 (M2-M6Ia) |
| Apparent magnitude (B) | 22.1 |
| Apparent magnitude (J) | 4.31 |
| Apparent magnitude (H) | 1.35 |
| Apparent magnitude (K) | 1.9 |
| B−V color index | +4.906 |
| Astrometry | |
| Radial velocity (Rv) | -49.42 km/s |
| Proper motion (μ) | RA: -1.841 mas/yr Dec.: -3.909 mas/yr |
| Distance | 14,200 ly (4,350 pc) |
| Details | |
| Radius | 1,145–1,240 R☉ |
| Luminosity | 276,000±10,000 L☉ |
| Temperature | 3,782±14 K |
| Age | 7.9 Myr |
| Other designations | |
| Westerlund 1 W26, W1–26, 2MASS J16470540-4550367, Westerlund 1 BKS AS, Westerlund 1 BKS A, Gaia EDR3 5940106041452150272 | |
| Database references | |
| SIMBAD | data |
Westerlund 1 W26 (commonly abbreviated to W26) or Westerlund 1 BKS AS is a red supergiant located at the outskirts of the Westerlund 1 super star cluster. It is one of the largest known stars and the most luminous supergiant stars discovered so far with radius calculated to be in excess of a thousand times the solar radius, and a luminosity of over 200,000 times the solar luminosity. If placed at the center of the Solar System, its photosphere would engulf the orbit of Jupiter.