Black holes

A mathematical shortcut for analyzing black hole collisions works even in cases where it shouldn’t. As astronomers use it to search for new classes of hidden black holes, others wonder: Why?

Ultrahigh-energy cosmic rays twist and turn on their way to Earth, which has made it nearly impossible to identify the colossal monsters that create them.

Black holes seemed to come only in sizes small and XXL. A new search strategy has uncovered a black hole of “intermediate” mass, raising hopes of more to come.

The zoo of spontaneously emerging particlelike entities known as quasiparticles has grown quickly and become more and more exotic. Here are a few of the most curious and potentially useful examples.

A supernova-like explosion dubbed the Camel appears to be the result of a newborn black hole eating a star from the inside out.

One black hole is nice, but astrophysicists can do a lot more science with 50 of them.

A new study shows that extreme black holes could break the famous “no-hair” theorem, and in a way that we could detect.

Small black holes were nowhere to be found, leading astronomers to wonder if they didn’t exist at all. Now a series of findings, including a “unicorn” black hole, has raised hopes of solving the decade-long mystery.

For decades, astronomers debated whether a particular smudge was close-by and small, or distant and huge. A new X-ray map supports the massive option.