Triple star systems are very common in the universe, but now astronomers have found a system where one of the stars is a black hole. They're located in the V404 Cygni system, about 8,000 light-years away. At the center is a black hole consuming a small star, while a third star is orbiting the black hole every 70,000 years or so. Astronomers had spotted this third star a long time ago, but only recently discovered that it's part of the system thanks to Gaia.

Astronomers have detected ultra-high-energy gamma rays coming from the center of the Milky Way, with nearly 100 events of more than 100 teraelectron volts of energy. Researchers aren't sure what's generating so many of these extreme events, but it's where the Milky Way's supermassive black hole, which is surrounded by neutron stars and white dwarfs that strip material from nearby stars, is located. And all of this is surrounded by dense gas reaching millions of degrees.

With 'Thousand Sails,' China joins the race to fill up Low Earth Orbit with mega-satellite constellations.