Viewing a single comment thread. View all comments

waylandsmith t1_iwau9m0 wrote

This is an interesting time to be asking that question, considering something that was just observed.

>The hypermassive star was produced by the merger of two smaller neutron stars. Normally such collisions result in neutron stars so massive that they collapse into a black hole almost instantaneously under their own gravity. But the latest observations revealed the monster star hovering in view for more than a day before it faded out of sight.

So, according to the observation, two neutron stars (which are always quite close to the critical mass for a black hole) merged, bringing the total mass much higher than the needed limit, but it took a significant amount of time for the observable neutron stars to 'fade away' into the black hole.

2

RevolutionaryAd4161 OP t1_iwax2sw wrote

Im assuming there are no alternative material types for neutron strars that would make them lese dense?

1

waylandsmith t1_iwb6ght wrote

Nope. Neutron stars exist in a narrow window of masses and densities and these characteristics have been confirmed in observations of them, at least the sort that we can detect (ones that are pulsars). The neutron star itself does have some structure, though, with various layers containing slightly different densities, the different forms being called "nuclear pasta". It has a gnocchi, spaghetti, lasagna, anti-spaghetti, and finally a 'swiss cheese' layer.

I'm glad that scientists get to indulge in whimsical naming once in a while. (the truth and beauty quarks got re-named top and bottom unfortunately).

2

Okonomiyaki_lover t1_iwthpfx wrote

The "material" of a neutron star is just that neutrons. All of the electrons in the atoms are pressed into the protons, turning them into neutrons. I forget is this is neutron or electon degeneracy pressure... But it ceases to be made of atoms at that point.

1