Universe

Just how big can a star become? The answer depends on when in cosmic history you’re asking the question

Despite years of debate and follow-up studies, an odd streak of cosmic light still defies a final explanation. Is it a giant black hole screaming through intergalactic space?

The science of the zodiac is more intriguing than astrology would have you think

Although astronomers have found thousands of exoplanets, the number of confirmed exomoons—and exorings—is still zero. But that may soon change

The collision of supermassive black holes shakes the entire cosmos, hard

A “disappearing” star in the Andromeda galaxy is the closest and best candidate for a newborn black hole that astronomers have ever seen

You might think galaxies can’t ever find each other in our runaway cosmos, but it turns out gravity can sometimes overcome even the stretching of space itself

Dating to only a billion years after the big bang, JADES-ID1 may be the earliest, most distant galaxy protocluster astronomers have ever seen

Astronomers puzzled out minuscule distortions in images of faraway galaxies taken by JWST in order to chart the invisible

From planet-scorching stellar outbursts to cataclysms so powerful they shiver the very fabric of spacetime, these are some of the biggest blasts our cosmos has to offer

A fresh look at the Helix Nebula captures new details of the cycle of stellar life and death

Puzzling red spots in images from the James Webb Space Telescope are probably young supermassive black holes obscured by dense cocoons of gas