The cinder will glow brightly for a short period of time and then fade rapidly. Such is the fate of neutron stars, because although born at $10^{11}$ K in the heart of a supernova, they have an extremely low heat capacity. Contrary to common belief - neutron stars are not supported by neutron degeneracy pressure. Yes, this contributes, but a ...

There are still plenty of protons and electrons (well ~10%). @WetSavannaAnimal one clue is that the direct URCA process could easily occur if the neutron star was not dominated by degenerate n. If the p/n ratio was high neutron stars would cool extremely fast. $\endgroup$ –

Neutron stars do not have a photon sphere. The Schwarzschild radius of a neutron star is about 3 km, which means you have to compress it within that size to create a black hole. This means that the photon sphere radius would be about 4.5 km, so to have a photon sphere you would need to cram the neutron star smaller than that.

2024年12月28日 · A neutron star is the final stage of the graviational collapse of a massive supergiant star. Except for black holes, neutron stars are the smallest and densest currently known class of stellar objects

2022年5月20日 · In that case neutron stars lie on a locus defined by $$ \frac{L}{L_{\odot}} = 1.9\times 10^{-9} \left(\frac{T}{10^{4}K}\right)^4 $$ So, contrary to what you you say in your question, most neutron stars could be cool and very, very faint and spend the majority of their (cooling) lives at the bottom or even bottom-right of the HR diagram. There ...

2021年10月15日 · What supports neutron stars is the repulsion provided by the strong nuclear force between closely-packed neutrons. The central pressure in a neutron star is an order of magnitude higher than ideal neutron degeneracy pressure. no, it's not quark degeneracy pressure, it's actual forces due to gluon exchange.

2014年11月30日 · At neutron star densities (a few $\times 10^{17}$ kg/m $^{3}$) the ratio of neutrons to protons is of order 100. (The number of protons equals the number of electrons). (The number of protons equals the number of electrons).

2021年7月3日 · Neutron stars are found to have masses in the rough range $1-3$ solar masses, while black holes can in principle have any mass. The radius of a neutron star is larger the Schwarzschild radius. The ratio between the neutron star Schwarzschild radius and two times the radius of the neutron star is called the neutron star compactness. If the ...

2013年3月21日 · Neutron stars are one of the least transparent objects in the universe. There are still lots of protons and free electrons, and most importantly the density of these charged species is extremely high.

2023年2月8日 · TL;DR A crude estimate would be that as many as 0.26% of stars in the Galaxy are neutron stars and 0.06% are black holes, but these figures are highly uncertain. Details. Neutron stars are almost undetectable once they have gone through the short-lived (10 million years or so) pulsar phase, so just counting neutron stars isn't going to give an ...