LBV 1806-20 is a blue supergiant star. It 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 is 5 million to 40 million times as bright as the Sun, at least 150 times as massive and at least 200 times as wide. It has a total system mass of around 130 solar masses and an estimated variable luminosity of around two million times that of the Sun.
LBV 1806-20 is a luminous blue variable (LBV) and likely binary star located nearly 40,000 light-years from the Sun, towards the center of the galaxy.
It is 2,000,000 times brighter than the Sun. 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 despite its brightness is not easily seen. It is located in the Sagittarius constellation but due to dust is not visible to the naked eye. Forty-five thousand light-years away on the other side of the Milky Way galaxy, it is blocked from view by dust clouds.
If it was located as near to the sun as this image suggests, the star’s light would completely swamp that of the sun, making it invisible and virtually undetectable.
The star is 1,135 times larger than the Sun. Located about 45,000 light-years from Earth, it is detectable only with infrared telescopes, because all of its visible light is absorbed by dust particles in space. 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, challenging our understanding of the formation of massive stars. When LBV 1806-20 was discovered in the 1990s, astronomers categorized it as a bright, short-lived blue star and estimated that it was at least a million times the mass of the Sun. 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. Because the star is so bright, it will burn out quickly, within a few million years, compared with the 10 billion-year lifespan estimated for the Sun. It is estimated at 2 million times as luminous as the sun which makes it one of the most luminous stars in the galaxy.