In 185 A.D., Chinese astronomers noted a "guest star" that mysteriously appeared in the sky and stayed for about 8 months.

Astronomers have recently completed a large survey of the sky using some of the powerful telescopes both on the ground and in space.

G299.2-2.9 is an intriguing supernova remnant found about 16,000 light years away in the Milky Way galaxy.

High-mass stars are important because they are responsible for much of the energy pumped into a galaxy over its lifetime.

In recent years, astronomers have found hundreds of planets orbiting stars other than our Sun.

Astronomers using NASA's Chandra X-ray Observatory have discovered the first pair of supermassive black holes in a spiral galaxy similar to the Milky Way.

VV 340, also known as Arp 302, is a textbook example of colliding galaxies seen in the very early stages of their interaction.

The Crab Nebula is one of the brightest sources of high-energy radiation in the sky.

This is NGC 3115, a galaxy located about 32 million light years from Earth. This composite image contains X-rays from Chandra as well as optical data from the Very Large Telescope.

A spinning neutron star is tied to a mysterious tail, or is it? Astronomers using NASA's Chandra X-ray Observatory have found a long, X-ray bright tail streaming away from the pulsar known as PSR J0357.