Astronomers think they have identified the remnant of a supernova recorded by Chinese astronomers in AD 386.
Two sources tens of millions of light-years away have sent puzzling X-ray flares blazing our way. Now astronomers think they might have the answer: intermediate-mass black holes.
China's Hard X-ray Modulation Telescope (HXMT) headed to orbit this past weekend.
HaloSat, a mini-satellite recently deployed from the International Space Station, is on the hunt for the universe's missing matter.
The Japanese space agency JAXA has released a timeline covering the Hitomi space observatory's failure last month. Salvage efforts continue but recovery appears unlikely.
The RXTE satellite, which reentered Earth's atmosphere over the tropics on April 30th, leaves behind a legacy of discoveries and data.