3C196.1 is a massive elliptical galaxy, the brightest member of a cluster of galaxies about three billion light-years away that is notable for its strong X-ray and radio emission. The rad...

Most stars with the mass of the sun or larger have one or more companion stars, but when and how these multiple stars form is one of the controversial central problems of astronomy. Grav...

The Cygnus Loop (also known as the Veil Nebula) is a supernova remnant, the detritus of the explosive death of a massive star about ten to twenty thousand years ago. Detailed modeling of ...

The path of light is bent by mass, an effect predicted by Einstein's theory of gravity, and when a massive galaxy or cluster lies along our line-of-sight to a more distant galaxy its matt...

Cambridge, MA - A new discovery reported in the Astrophysical Journal Letters might lay claim to title of the most unusual extreme class of astronomical object: very high energy (VHE)...

Most galaxies lie in clusters containing from a few to thousands of other galaxies. Our Milky Way, for example, belongs to the Local Group cluster of about fifty galaxies whose other lar...

Stellar variability has long offered insights into stars' physical properties. The star Mira (Omicron Ceti), for example, was so-named in 1596 by Dutch astronomers who were amazed by its...

The young star Eta Carinae shines prominently in the skies of the southern hemisphere. Although located relatively far away from Earth (about seven thousand light-years away, as compared...

One year ago this week astronomers discovered an unusual object moving through space not too far from the Earth's orbit. In just a few days they realized it could not be a normal asteroid...

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