Q star

Hypothetical compact star

A Q-star, also known as a grey hole, is a hypothetical type of a compact, heavy neutron star with an exotic state of matter. Such a star can be smaller than the progenitor star's Schwarzschild radius and have a gravitational pull so strong that some light, but not all photons, can escape.^{[citation needed]} The Q stands for a conserved particle number. A Q-star may be mistaken for a stellar black hole.^[1]

Types of Q-stars

Q-ball^[2]
B-ball, stable Q-balls with a large baryon number B. They may exist in neutron stars that have absorbed Q-ball(s).^[2]

References

^ *Miller, J. C.; Shahbaz, T.; Nolan, L. A. (1998). "Are Q-stars a serious threat for stellar-mass black hole candidates?". Monthly Notices of the Royal Astronomical Society. 294 (2): L25–L29. arXiv:astro-ph/9708065. Bibcode:1998MNRAS.294L..25M. doi:10.1046/j.1365-8711.1998.01384.x.
^ ^a ^b Kusenko, Alexander (2006). Properties and signatures of supersymmetric Q-balls. workshop on Exotic Physics with Neutrino Telescopes. Uppsala, Sweden. arXiv:hep-ph/0612159. Bibcode:2006hep.ph...12159K.

Early Late Main sequence O B A F G K M Subdwarf O B WR OB Subgiant Giant Blue Red Yellow Bright giant Supergiant Blue Red Yellow Hypergiant Yellow Carbon S CN CH White dwarf Chemically peculiar Am Ap/Bp CEMP HgMn He-weak Barium Lambda Boötis Lead Technetium Be Shell B[e] Helium Extreme Blue straggler
Remnants	Compact star Parker's star White dwarf Helium planet Neutron Radio-quiet Pulsar Binary X-ray Magnetar Stellar black hole X-ray binary Burster SGR
Hypothetical	Blue dwarf Black dwarf Exotic Boson Electroweak Strange Preon Planck Dark Dark-energy Quark Q Black hole star Black Hawking Quasi-star Gravastar Thorne–Żytkow object Iron Blitzar White hole