How Are Black Holes Formed and What Are Their Key Facts?

[AleksanderPhy]

Well on physics we have rule what says: when objects mass is very big then it have's strong gravity so black hole must be have very big mass

 

[Bernie G]

Sometimes, even if a dead star leaves a neutron star behind, this star can collect enough additional mass from surrounding gas to collapse into a black hole.

It's also possible for two neutron stars to collide and, because their combined mass is so great, only a black hole is left behind.

Not so. The most massive neutron star which has been observed is about 2 solar masses. The smallest black hole observed is about 5 solar masses. Draw your own conclusions.

 

[SteamKing]

Not so. The most massive neutron star which has been observed is about 2 solar masses. The smallest black hole observed is about 5 solar masses. Draw your own conclusions.

There may be BHs which are smaller than 5 solar masses, but we just haven't observed them. There's no violation of any fundamental physics laws if smaller BHs exist.

Two neutron stars have been shown in simulation to merge into a single object which forms a BH.

http://www.iflscience.com/space/what-happens-when-neutron-stars-collide

 

[Neon]

There may be BHs which are smaller than 5 solar masses, but we just haven't observed them. There's no violation of any fundamental physics laws if smaller BHs exist.

Two neutron stars have been shown in simulation to merge into a single object which forms a BH.

http://www.iflscience.com/space/what-happens-when-neutron-stars-collide

Bhs smaller than 5 sm are possible.Those bh are so light than few clues are released ( x ray...) so maybe in the future we will find super light bhs.

 

[|Glitch|]

Gravity effects the entire electromagnetic spectrum, not just photons or objects with mass, correct? Therefore, would not the gravity of a black hole, once the event horizon is crossed, also "consume" infrared radiation? If that is true, than would not the temperature of a black hole at its event horizon always be absolute zero? Would that not contradict quantum field theory in curved space-time that predicts that event horizons emit radiation like a black body with a finite temperature?