What does the supermassive black hole lurking at the center of our galaxy look like?It's a deceptively simple question. Although our local cosmic abyss, named Sgr A* (short for Sagittarius A* ...

The ghosts of stars are up to their usual mischief. By Dennis Overbye Just in time for Halloween, two black holes are in the news. One is a serial killer, on the verge of devouring its second star ...