A black hole that hasn't been heard of since 1989 has suddenly become active again and is now the brightest object in the X-ray sky.
By using the world's preeminent telescopes, astronomers peer behind a curtain of dust to find a giant star-making factory known as "Sparky."
A giant star in the Canis Majoris constellation isn't acting like itself, and scientists are doing their best to figure out why.
Speaking to Congress, two astronomers from SETI describe the chances of finding aliens as almost 100 percent.
Scientists pull a needle out of a haystack and identify a star that dates back to shortly after the Big Bang.
Interstellar echoes from a flaring neutron star have allowed astronomers to solve a mystery -- pinpointing the star's location.
Astronomers have used a trick of general relativity to look around a corner, of sorts, and view a massive, distant galaxy with remarkable clarity.
A team of astronomers has calculated the weight of the Milky Way to a high degree of precision by observing stars outside the galactic disc.
The Very Large Telescope has spotted signs that may indicate the presence of the oldest stars in the universe -- formed from matter created by the Big Bang.
Astronomers have pieced together Hubble data to observe a collision between knots of matter in the jet of a supermassive black hole for the first time.