Pistol Star. Hubble Space Telescope infrared image of the Pistol Star (white), one of the brightest & largest in our galaxy, & the nebula (red) around it. The star is 100 times more massive than our Sun, & is 10 million times more luminous. Its diameter is larger than Earth's orbit. It is rapidly shedding its outer layers to form the Pistol nebula. The Pistol Star appears very dim from Earth at visible wavelengths because dust clouds block its light. It lies 25,000 light years away near the galactic centre in the constellation of Sagittarius. Image taken by Hubble's Near- Infrared & Multi-Object Spectrometer (NICMOS).