Question

What are Quark Stars and how do they differ from neutron stars?

Answer 1

I wanted to say that Quark stars are the stars in the constellation of Donald the Duck, but I really don't know what quark stars are.. . Maybe they are stars made up of the subatomic quark particle, just as a neutron star is made up of neutrons.

Answer 2

You speak as though they exist. Quark stars are hypothesised, but none have as yet been found, though there is one candidate star, previously thought to be a neutron star, that may perhaps be reclassified as a quark star. Quark stars, were they to exist, would be intermediate between neutron stars and black holes in size and density. . . They would be most unusual if they did exist, as the principle of containment suggests that quarks are not found alone as separate particles but are found bonded together in threes as hadrons (protons, neutrons and electrons). But who knows what the effect of enormous pressure can produce, as regards matter continuing to obey the established laws of physics?. . Do you perhaps mean Quasars? (originally called QUASi-stellAR objects, but contracted to quasars) Are you under the impression that quasar is a contraction of Quark Star?. . Properties of quasars. More than 60 000 quasars are known, all observed spectra have shown considerable redshifts, ranging from 0.06 to the recent maximum of 6.4. Therefore, all known quasars lie at great distances from us, the closest being 240 Megaparsecs (780 million ly) away and the farthest being 4 Gigaparsecs(13 billion ly) away. . . Most quasars are known to lie above 1.0 Gigaparsecs in distance; since light takes such a long time to cover these great distances, we are seeing quasars as they existed long ago—the universe as it was in the distant past.. . Although faint when seen optically, their high redshift at great distance imply that quasars are the brightest objects in the known universe. The currently brightest known quasar is the ultraluminous 3C 273 in the constellation of Virgo. It has an average apparent magnitude of 12.8 (when observing with a telescope), but it has an absolute magnitude of −26.7. . . So from a distance of 10 parsecs, this object would shine in the sky about as bright as our sun. This quasar's luminosity is, therefore, about 2 trillion (2 × 10^12) times that of our sun, or about 100 times that of the total light of average giant galaxies like our Milky Way.

Answer 3

put simply, they think there might be another stage after neutron star, when a star goes supernova it leaves behind a neutron star, they think that the star couldget even more dense and go from purely neutrons, to purely quarks.

Answer 4

QUARK STARS.. . Neutron stars are the dense cinders of massive stars which have gone supernova and crushed the matter in their cores to densities of 10^14 grams/cc. At these densities, equal to that of nuclear matter, most of the protons and electrons have combined to create neutrons, so that the core is nearly 100% pure neutrons. The cinder is prevented from further gravitational collapse because neutrons are particles with 1/2-unit of quantum spin, and only two of these can exist in the same quantum state. This produces what is called Fermi Degeneracy Pressure which at these densities and neutron star masses, can be as strong as gravity, but a repulsive force. . . Neutrons are composed of three quarks, which are also capable of generating the same kind of degeneracy pressure, but first you have to compress the neutron star to densities of 10^16 grams/cc or higher. This requires an amount of mass in the neutron star that puts it nearly at the black hole limit for its size...about 25 kilometers in radius or less. At these densities, the neutrons in the core of this object begin to dissolve into their constituent quarks, and so in the deep interior of the cinder you end up with a 'gas' of quarks. As you continue to crank up the density even higher, the quark-state encompasses more and more of the neutron star. The problem is that such 'quark stars' are nearly the same size as the black hole limit for the amount of mass and size, so when you factor-in the relativistic effects, quark stars are probably a very unstable and fleeting phase in the life of a very massive neutron star.