Black Hole
A black hole is an astronomical object whose gravity is so strong that nothing—even light—can escape from within its event horizon. It forms when a massive star’s core collapses or through other processes, and may have an accretion disk of infalling matter that emits radiation. Supermassive black holes at galaxy centers influence stellar orbits, and mergers produce gravitational waves.
Source: nasa.gov
APODs including "Black Hole"
At Last GLAST
11/06/2018
Rising through a billowing cloud of smoke, a long time ago from a planet very very close by, this Delta II rocket left Cape Canaveral Air Force Station's launch pad 17-B at 12:05 pm EDT on June 11, 2008. Snug in the payload section was GLAST, the Gamma-ray Large Area Space Telescope. GLAST's detector technology was developed for use in terrestrial particle accelerators. So from orbit, GLAST can detect gamma-rays from extreme environments above the Earth and across the distant Universe, including supermassive black holes at the centers of distant active galaxies, and the sources of powerful gamma-ray bursts. Those formidable cosmic accelerators achieve energies not attainable in earthbound laboratories. Now known as the Fermi Gamma-ray Space Telescope, on the 10 year anniversary of its launch, let the Fermi Science Playoffs begin.