Reshared post from +Wayne Radinsky
Birth of a black hole. In the 1960's, satellites were launched to detect Soviet nuclear tests using gamma rays, but they discovered gamma ray bursts from space instead. 30 years later, it was determined that they happened randomly all around the sky, and at great distances. Then it was discovered that they coincided with supernovae that could be seen with visible light. And some were billions of light-years away — the entire breadth of the universe. Supercomputer simulations show these gamma ray bursts can happen in narrow jets as a result of black holes being born, either from two stars merging, or from a supernova of one star, and can be seen if the jets happen to be pointing in the right direction, towards earth. The shortest bursts happen when two stars form a black hole, and longer bursts, lasting a few minutes, happen when one large star goes supernova. But hours-long gamma ray bursts can happen when a star collides with a supermassive black hole, such as the supermassive black hole at the center of M87, which has 6.6-billion solar masses. The "jets" happen because matter falling into a black hole becomes ionized, and forms magnetic fields billions of times more powerful than the sun's magnetic field lines, and ionized matter gets propelled by the magnetic fields into jets.