Stellar black hole Trivia Questions

Due to extreme gravitational time dilation, an outside observer sees a clock near the horizon tick much slower.

No light can escape the event horizon; any radiation we detect comes from surrounding matter heated to extreme temperatures outside it.

Stars below about 20 solar masses typically end as neutron stars or white dwarfs; only heavier stars collapse directly into black holes.

Black hole spin depends on the angular momentum of the collapsing star and later accretion, so spin rates vary widely.

Observations show stellar black holes can exceed 50 solar masses, like Cygnus X-1 at about 21 solar masses, but some reach 100 solar masses via mergers.

Supermassive black holes are rare but stellar black holes are far more numerous, with estimates of 100 million in the Milky Way alone.

Very massive stars can collapse directly into a black hole via a 'failed supernova'—the core implodes silently.

Gaia BH1, about 1,560 light-years away, is the nearest confirmed stellar black hole, but some candidates may be closer.