Using Event Horizon Telescope observations of M87's black hole from 2017, 2018 and 2021, "astronomers have found some changes in this now iconic image that could be caused by variations in the ...

The New Crescent Society, which is organizing the Greenwich event with the Royal Observatory, is hoping moon sighting will become fully established in Britain and be used by mosques.

For a few brief nights each year, you get a rare chance to watch a monster blink. The Event Horizon Telescope collaboration ...

What if the Milky Way’s central “black hole” isn’t a black hole at all? A new model proposes that an ultra-dense dark matter core could mimic its gravitational pull.

Previous observations of stars whipping around an unseen mass—especially a bright star called S2—have pointed to an object ...