Have We Really Just Seen The Birth Of A Black Hole?

"In the failed supernova/black hole formation picture of this event, the transient is driven by the failed supernova. The star we see before the event is a red supergiant -- so you have a compact core (size of ~earth) out the hydrogen burning shell, and then a huge, puffy extended envelope of mostly hydrogen that might extend out to the scale of Jupiter's orbit.  This envelope is very weakly bound to the star.  When the core of the star collapses, the gravitational mass drops by a few tenths of the mass of the sun because of the energy carried away by neutrinos.  This drop in the gravity of the star is enough to send a weak shock wave through the puffy envelope that sends it drifting away.  This produces a cool, low-luminosity (compared to a supernova, about a million times the luminosity of the sun) transient that lasts about a year and is powered by the energy of recombination.  All the atoms in the puffy envelope were ionized -- electrons not bound to atoms -- as the ejected envelope expands and cools, the electrons all become bound to the atoms again, which releases the energy to power the transient.  What we see in the data is consistent with this picture."