Two elements hint Cas A underwent a quark nova — a theoretical explosion that leaves behind a quark star — just days after the original supernova.

The Case of Missing Iron in Cassiopeia A

Are double-humped super-luminous supernovae happening when a neutron star converts to a quark star?

Are double-humped super-luminous supernovae happening when a neutron star converts to a quark star?

The 2012 discovery of the Higgs boson, or.

The sizes of a neutron star and a quark star compared to the Grand Canyon. The smallest, most massive, most compressed neutron star possible is about 17 kilometers in diameter. A quark star can be smaller than 11 kilometers diameter. The canyon is 29 kilometers from rim to rim. In reality this scene couldn't exist; the entire Earth would collapse almost instantly to a thin layer coating the surface of either superdense star. Illustration by D. Berry / Chandra X-ray Center.

Two groups of astronomers say they have found superdense objects even smaller and weirder than neutron stars, and made of a substance like nothing else in the universe.

A white dwarf, a neutron star or even a strange quark star are all still made of fermions. The Pauli degeneracy pressure helps hold up the stellar remnant against gravitational collapse, preventing a black hole from forming.

Ask Ethan: What's The Difference Between A Fermion And A Boson?

In a neutron star (left), the quarks that comprise the neutrons are confined inside the neutrons. In a quark star(right), the quarks are free, so they take up less space and the diameter of the star is smaller. (Illustration: NASA/CXC/M.

Quark Star Plays Role in New Theory for Brightest Supernovae

Artist illustration of supernova. Credit: NASA An exploding star in our home galaxy might be visible to Earth in the next 50 years, astronomers say in a new calculation of the odds of a nearby supernova.

Neutron stars tend to lie in the range of 1.4 to 2 solar masses. Any star with a neutron star’s density that’s over 10 solar masses has to become a black hole. That leaves a bit of a gap, although there is evidence of stellar black holes down to only 3 solar masses. The theoretical gap for strange stars to form may only be in the 2 to 3 solar masses range.

Astronomy Without A Telescope - Strange Stars - Universe Today

What are Quark Stars?

Astronomers have theorized there could be an intermediate stage between neutron stars and black holes called quark stars.

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Star Nursery Rug

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Quark stars: How can a supernova explode twice?

What do you get when you melt a neutron star? An unimaginably dense lump of strange matter and a whole new celestial beast, says Anil Ananthaswamy

Structure of Quark Star vs Neutron Star

Structure of Quark Star vs Neutron Star