Physics Gifts

- Art Gallery -

A strange star is a quark star made of strange quark matter. They form a subgroup under the quark star category.[1][2][3]

Strange stars might exist without regard to the Bodmer–Witten assumption of stability at near-zero temperatures and pressures, as strange quark matter might form and remain stable at the core of neutron stars, in the same way as ordinary quark matter could.[4] Such strange stars will naturally have a crust layer of neutron star material. The depth of the crust layer will depend on the physical conditions and circumstances of the entire star and on the properties of strange quark matter in general.[5] Stars partially made up of quark matter (including strange quark matter) are also referred to as hybrid stars.[6][7][8][9]

This theoretical strange star crust is proposed to be a possible reason behind fast radio bursts (FRBs). This is still theoretical, but there is good evidence[6][7][8][9] that the collapse of these strange star crusts may be an FRB point of origin.

Characteristics

Recent theoretical research has found the mechanisms by which the quark stars with "strange quark nuggets"[10] may decrease the objects' electric fields and the densities from previous theoretical expectations, causing such stars to appear nearly indistinguishable from ordinary neutron stars. This suggests that many, or even all, known neutron stars might be the strange stars. However, the investigating team of Jaikumar, Reddy, and Steiner (2006)[10] made some fundamental assumptions that led to uncertainties in their results significant enough that the question is not settled. More research, both observational and theoretical, remains to be done on strange stars in the future.[10]

Other theoretical work contends that :

A sharp interface between quark matter and the vacuum would have very different properties from the surface of a neutron star.[11]

Addressing key parameters like surface tension and electrical forces that were neglected in the original study, the results show that as long as the surface tension is below a low critical value, the large strangelets are indeed unstable to fragmentation and strange stars naturally come with complex strangelet crusts, analogous to those of neutron stars.[11]
Crust collapse

For a strange star's crust to collapse, it must accrete matter from its environment in some form.

The release of even small amounts of its matter causes a cascading effect on the star's crust. This is thought to result in a massive release of magnetic energy as well as electron and positron pairs in the initial phases of the collapsing stage. This release of high energy particles and magnetic energy in such a short period of time causes the newly released electron / positron pairs to be directed towards the poles of the strange star due to the increased magnetic energy created by the initial secretion of the strange star's matter. Once these electron / positron pairs are directed to the star's poles, they are then ejected at relativistic velocities, which is proposed to be one of the causes of FRBs.
Primordial strange stars

Theoretical investigations have revealed that quark stars might not only be produced from neutron stars and powerful supernovae, they could also be created in the early cosmic phase separations following the Big Bang.[12]

If these primordial quark stars can transform into strange quark matter before the external temperature and pressure conditions of the early universe renders them unstable, they might become stable, if the Bodmer–Witten assumption holds true. Such primordial strange stars could survive to this day.[12]
References

Alcock, Charles; Farhi, Edward; Olinto, Angela (1986). "Strange stars". Astrophys. J. 310: 261–272. Bibcode:1986ApJ...310..261A. doi:10.1086/164679.
P., Haensel; R., Schaeffer; J.L., Zdunik (1986). "Strange quark stars". Astronomy and Astrophysics. 160.
Weber, Fridolin; et al. (1994). Strange-matter Stars. Proceedings: Strangeness and Quark Matter. World Scientific. Bibcode:1994sqm..symp....1W.
Stuart L. Shapiro; Saul A. Teukolsky (20 November 2008). Black Holes, White Dwarfs, and Neutron Stars: The Physics of Compact Objects. John Wiley & Sons. pp. 2ff. ISBN 978-3-527-61767-8.
Kodama Takeshi; Chung Kai Cheong; Duarte Sergio Jose Barbosa (1 March 1990). Relativistic Aspects Of Nuclear Physics - Rio De Janeiro International Workshop. #N/A. pp. 241–. ISBN 978-981-4611-69-5.
Alford, Mark G.; Han, Sophia; Prakash, Madappa (2013). "Generic conditions for stable hybrid stars". Physical Review D. 88 (8): 083013.arXiv:1302.4732. Bibcode:2013PhRvD..88h3013A. doi:10.1103/PhysRevD.88.083013. S2CID 118570745.
Goyal, Ashok (2004). "Hybrid stars". Pramana. 62 (3): 753–756.arXiv:hep-ph/0303180. Bibcode:2004Prama..62..753G. doi:10.1007/BF02705363. S2CID 16582500.
Benić, Sanjin; Blaschke, David; Alvarez-Castillo, David E; Fischer, Tobias; Typel, Stefan (2015). "A new quark-hadron hybrid equation of state for astrophysics". Astronomy & Astrophysics. 577: A40.arXiv:1411.2856. Bibcode:2015A&A...577A..40B. doi:10.1051/0004-6361/201425318. S2CID 55228960.
Alvarez-Castillo, D; Benic, S; Blaschke, D; Han, Sophia; Typel, S (2016). "Neutron star mass limit at 2 M⊙ supports the existence of a CEP". The European Physical Journal A. 52 (8): 232.arXiv:1608.02425. Bibcode:2016EPJA...52..232A. doi:10.1140/epja/i2016-16232-9. S2CID 119207674.
Jaikumar, P.; Reddy, S.; Steiner, A. W. (2006). "Strange star surface: A crust with nuggets". Physical Review Letters. 96 (4): 041101.arXiv:nucl-th/0507055. Bibcode:2006PhRvL..96d1101J. doi:10.1103/PhysRevLett.96.041101. PMID 16486800. S2CID 7884769.
Alford, Mark G.; Rajagopal, Krishna; Reddy, Sanjay; Steiner, Andrew W. (2006). "Stability of strange star crusts and strangelets". Physical Review D. 73 (11): 114016.arXiv:hep-ph/0604134. Bibcode:2006PhRvD..73k4016A. doi:10.1103/PhysRevD.73.114016. S2CID 35951483.

Witten, Edward (1984). "Cosmic separation of phases". Physical Review D. 30 (2): 272–285. Bibcode:1984PhRvD..30..272W. doi:10.1103/PhysRevD.30.272.

Further reading

Zhang, Yue; Geng, Jin-Jun; Huang, Yong-Feng (2018). "Fast radio bursts from the collapse of strange star crusts". The Astrophysical Journal. 858 (2): 88.arXiv:1805.04448. Bibcode:2018ApJ...858...88Z. doi:10.3847/1538-4357/aabaee. S2CID 119245040. – Original scientific paper source

"Are mysterious fast radio bursts coming from the collapse of strange star crusts?". – Simpler breakdown of said scientific paper.

vte

Stars
Formation

Accretion Molecular cloud Bok globule Young stellar object
Protostar Pre-main-sequence Herbig Ae/Be T Tauri FU Orionis Herbig–Haro object Hayashi track Henyey track

Evolution

Main sequence Red-giant branch Horizontal branch
Red clump Asymptotic giant branch
super-AGB Blue loop Protoplanetary nebula Planetary nebula PG1159 Dredge-up OH/IR Instability strip Luminous blue variable Blue straggler Stellar population Supernova Superluminous supernova / Hypernova

Spectral classification

Early Late Main sequence
O B A F G K M Brown dwarf WR OB Subdwarf
O B Subgiant Giant
Blue Red Yellow Bright giant Supergiant
Blue Red Yellow Hypergiant
Yellow Carbon
S CN CH White dwarf Chemically peculiar
Am Ap/Bp HgMn Helium-weak Barium Extreme helium Lambda Boötis Lead Technetium Be
Shell B[e]

Remnants

White dwarf
Helium planet Black dwarf Neutron
Radio-quiet Pulsar
Binary X-ray Magnetar Stellar black hole X-ray binary
Burster

Hypothetical

Blue dwarf Green Black dwarf Exotic
Boson Electroweak Strange Preon Planck Dark Dark-energy Quark Q Black Gravastar Frozen Quasi-star Thorne–Żytkow object Iron Blitzar

Stellar nucleosynthesis

Deuterium burning Lithium burning Proton–proton chain CNO cycle Helium flash Triple-alpha process Alpha process Carbon burning Neon burning Oxygen burning Silicon burning S-process R-process Fusor Nova
Symbiotic Remnant Luminous red nova

Structure

Core Convection zone
Microturbulence Oscillations Radiation zone Atmosphere
Photosphere Starspot Chromosphere Stellar corona Stellar wind
Bubble Bipolar outflow Accretion disk Asteroseismology
Helioseismology Eddington luminosity Kelvin–Helmholtz mechanism

Properties

Designation Dynamics Effective temperature Luminosity Kinematics Magnetic field Absolute magnitude Mass Metallicity Rotation Starlight Variable Photometric system Color index Hertzsprung–Russell diagram Color–color diagram

Star systems

Binary
Contact Common envelope Eclipsing Symbiotic Multiple Cluster
Open Globular Super Planetary system

Earth-centric
observations

Sun
Solar System Sunlight Pole star Circumpolar Constellation Asterism Magnitude
Apparent Extinction Photographic Radial velocity Proper motion Parallax Photometric-standard

Lists

Proper names
Arabic Chinese Extremes Most massive Highest temperature Lowest temperature Largest volume Smallest volume Brightest
Historical Most luminous Nearest
Nearest bright With exoplanets Brown dwarfs White dwarfs Milky Way novae Supernovae
Candidates Remnants Planetary nebulae Timeline of stellar astronomy

Related articles

Substellar object
Brown dwarf Sub-brown dwarf Planet Galactic year Galaxy Guest Gravity Intergalactic Planet-hosting stars Tidal disruption event

The Most Dangerous Stuff in the Universe - Strange Stars Explained (V)

Physics Encyclopedia

World

Index

Hellenica World - Scientific Library

Retrieved from "http://en.wikipedia.org/"
All text is available under the terms of the GNU Free Documentation License