The Pistol Star is one of the most luminous and most massive stars known; it is about 10 million
times brighter than the Sun and 100 times more massive. The Pistol Star
lies at the center of the Pistol Nebula, which it created
it by expelling up to 10 solar masses of gas in giant outbursts some 4,000
to 6,000 years ago. Both star and nebula are in the Quintuplet
Cluster, close to the center of our galaxy, about 25,000 light-years
away; yet despite this immense distance, the Pistol Star would be visible
to the naked eye, as a fourth magnitude star, if it were not obscured by
dust clouds in the plane of the Milky Way.
|The Pistol Star is the bright white dot in the center
of this image taken with the Near Infrared Camera and Multi-Object
Spectrometer (NICMOS) on the Hubble Space Telescope.
Credit: Don F. Figer (UCLA) and NASA
The most powerful telescopes cannot see the Pistol Star at visible wavelengths;
however, 10% of its infrared light reaches
Earth, putting it within reach of infrared telescopes. Factoring in all
the material the Pistol Star has shed in its brief lifetime, this extraordinary
object may have started out with a mass of up to 200 solar masses –
larger than the maximum stellar mass anticipated by contemporary theories
of stellar evolution.