New data obtained on the apparent celestial couple, NGC 5011 B and C, taken with the 3.6-m ESO telescope, reveal that the two galaxies are not at the same distance, as was believed for the past 23 years. The observations show that NGC 5011C is not a giant but a dwarf galaxy, an overlooked member of a group of galaxies in the vicinity of the Milky Way.

Scientists were startled when they discovered in 2004 that the center of our galaxy is emitting gamma rays with energies in the tens of trillions of electronvolts.

Imagine two stars with winds so powerful that they eject an Earth's worth of material roughly once every month. Next, imagine those two winds colliding head-on. Such titanic collisions produce multimillion-degree gas, which radiates brilliantly in X-rays. Astronomers have conclusively identified the X-rays from about two-dozen of these systems in our Milky Way. But they have never seen one outside our galaxy - until now.

Like cold case investigators, astronomers have used NASA's Chandra X-ray Observatory to uncover evidence of a powerful outburst from the giant black hole at the Milky Way's center.

A superbubble in space, caught in the act of forming, can help scientists better understand the life and death of massive stars, say researchers at the University of Illinois at Urbana-Champaign.

A new image from the Hubble Space Telescope shows N90, one of the star-forming regions in the Small Magellanic Cloud. The rich populations of infant stars found here enable astronomers to examine star forming processes in an environment that is very different from that in our own Milky Way.

Astronomers have found evidence of a supermassive black hole at the heart of a dwarf elliptical galaxy about 54 million light years away from the Milky Way galaxy where Earth resides.