first picture of a black hole, april 2019

a black hole is an object which has a mass extremely big for it's size and has gravity so strong, nothing can escape it

they're created in a supernova explosion when a big star's core collapses or falls upon itself

R = 2MG/c^2 (R=radius of black hole, M=mass, G=gravitational constant, c=light speed, when R > geometric radius of black hole)