What if Neutron Stars Collide: Matter, Mass & Metal

[drakken1985]

what if...Neutron stars

I know likely its been answered but if two neutron stars collid, it wouldn't seem that there combined massess would forum a black hole...if I recall that any matter striking the surface of a neutron star impacts with such violence that there is a massive explosion. So I would think if two neutron stars collided the massess couldn't combine being the matter is converted into energy and blown off the stars at the stars' poles.

But would it be possible to remove matter from a neutron star...and what would that matter be like besides very heavy? Would the matter be a metal perhaps? Considering its matter consisting of neutrons--I would imagine it would be superconductive.

 

[DaveC426913]

But would it be possible to remove matter from a neutron star...and what would that matter be like besides very heavy?

Neutronium only exists under those incredible pressures. Were you to remove it, it would expand rapidly (essentially explode) to become normal matter.

 

[Chronos]

The gravity of neutron stars is so immense, very little mass would escape a collision. And yes, it is widely believed neutron star mergers result in black holes. It is less clear that a simple core collapse event can produce a black hole. We've seen some very massive stars leave a neutron star remnant instead of a black hole.

 

[twofish-quant]

But would it be possible to remove matter from a neutron star...and what would that matter be like besides very heavy? Would the matter be a metal perhaps? Considering its matter consisting of neutrons--I would imagine it would be superconductive.

If you take neutron star matter and then remove the pressure then you (probably) will get iron vapor. What you do is to calculate the lowest energy state. At high pressure, everything turns into neutronium, but once you remove the pressure, then the lowest energy state is iron nuclei.

I say "probably" because it's vaguely possible that if you pressurize something and then depressurize, it won't go into the lowest energy state (think diamonds). Although for neutron star matter, the energy difference between pure neutrons and iron nuclei at zero pressure is high enough so that this is unlikely.

One other thing is that colliding neutron stars is the favorite candidate for gamma ray bursts.

 

[Chalnoth]

One other thing is that colliding neutron stars is the favorite candidate for gamma ray bursts.

Well, there are two distinct classes of GRB's, and I *think* colliding neutron stars are a candidate for one of the two classes. I forget which.

 

[ImaLooser]

We've seen some very massive stars leave a neutron star remnant instead of a black hole.

Tell me more, please.

 

[ImaLooser]

I know likely its been answered but if two neutron stars collid, it wouldn't seem that there combined massess would forum a black hole...if I recall that any matter striking the surface of a neutron star impacts with such violence that there is a massive explosion. So I would think if two neutron stars collided the massess couldn't combine being the matter is converted into energy and blown off the stars at the stars' poles.
.

Converting, say 10% of the mass to energy would be an awful lot of energy. It would have been noticed.

 

[D H]

One other thing is that colliding neutron stars is the favorite candidate for gamma ray bursts.

Well, there are two distinct classes of GRB's, and I *think* colliding neutron stars are a candidate for one of the two classes. I forget which.

It's short gamma ray bursts that are conjectured to result from colliding neutron stars. Long duration GRBs most likely result from core collapse supernova, and possibly a from a supermassive black hole (somewhat slowly) devouring a compact star. Short duration GRBs are a beast of a different color. They differ from their long duration counterparts not only in duration but also in spectrum. The short duration GRBs were long conjectured to result from the collision between a co-orbiting pair of neutron stars or between co-orbiting neutron star and a stellar-sized black hole. GRB 050509B, observed in May 2005, pretty much ruled out every other plausible cause. Recent simulations of the collision of a neutron star with another or with a stellar black hole match observations.

These short duration GRBs pack an incredible punch in an incredibly short period of time. A whole lot of mass is being converted into energy in very short order.