Cosmology

Astronomers using the James Webb Space Telescope have spotted what may be the smallest known brown dwarf, a "failed star" that's only three or four times larger than Jupiter.

While hunting for dark matter, astronomers accidentally discovered the first known stellar stream stretching between galaxies. The trail of stars is also the longest ever seen.

Our best observations can't come up with a single answer for how quickly the universe is expanding. Maybe that's because our galaxy is at the center of a giant void.

Researchers recently detected an "ultra-high-energy" cosmic ray, which is the most powerful since the famous "Oh My God" particle was detected in 1991. They have no idea where it came from.

Dark matter may come in multiple particles and weights, similar to the ordinary elements on the periodic table, a new theory suggests.

A white dwarf spotted by the Gaia telescope was predicted to smash into our solar system in 29,000 years. But we'll be safe after all.

Scientists made a twin version of our universe, showing the evolution of all forms of matter and energy, in the biggest cosmological computer simulation to date.

Two conflicting methods to measure the expansion rate of the universe give different results, but researchers could resolve the disparity by watching merging neutron stars explode.

A new set of simulations suggests that the unusual brightness of early galaxies discovered by the James Webb telescope could be because of a strange, rapid-burst mode of star formation.

NASA's James Webb Space Telescope has spotted a distant supernova that appears three times in the same photo. The new observations could help solve one of the universe's biggest inconsistencies.