This isotope is found at a ratio of about one per 2,500 helium-4 ions, the latter being the common version of helium.

Although we know that supermassive black holes (millions of times the mass of our sun) lurk at the center of most galaxies, ...

A black hole 600,000 times the mass of the Sun was discovered close to the Milky Way, and it is shooting stars at us. Home to a monster black hole ...

Twice a year the sun bursts through a hole in a mountain in eastern Switzerland and, like a giant spotlight, briefly ...

Astronomers are investigating the longest and most energetic bursts of X-rays seen from a newly awakened black hole. Watching this strange behavior unfold in real time offers a unique opportunity to ...