LBV 1806−20
Infrared image of Cluster 1806_20. LBV 1806−20 is the brightest star, on the left. Credit: Hubble Space Telescope | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 18h 08m 40.31s |
| Declination | −20° 24′ 41.1″ |
| Characteristics | |
| Evolutionary stage | candidate LBV |
| Spectral type | O9 - B2 |
| Apparent magnitude (J) | 13.93 |
| Apparent magnitude (H) | 10.75 |
| Apparent magnitude (K) | 8.89 |
| Astrometry | |
| Distance | 8.7k pc |
| Details | |
| Mass | 36 M☉ |
| Radius | 46-145 R☉ |
| Luminosity | ~2,000,000 L☉ |
| Temperature | 18,000–32,000 K |
| Age | 3.0 – 4.5 Myr |
| Other designations | |
| 2MASS J18084031-2024411 | |
| Database references | |
| SIMBAD | data |
LBV 1806−20 is a candidate luminous blue variable (LBV) and likely binary star located around 28,000 light-years (8,700 pc) from the Sun, towards the center of the Milky Way. It has an estimated mass of around 36 solar masses and an estimated variable luminosity of around two million times that of the Sun. It is highly luminous but is invisible from the Solar System at visual wavelengths because less than one billionth of its visible light reaches us.
When first discovered, LBV 1806−20 was considered both the most luminous and most massive star known, which challenged scientific understanding of the formation of massive stars. Recent estimates place it somewhat nearer to Earth, which when combined with its binary nature mean that it is now well within the expected range of parameters for extremely luminous stars in the galaxy. It is estimated at 2 million times as luminous as the sun which makes it one of the most luminous stars in the galaxy.