View source for Astronomy:Quark-nova

{{short description|Hypothetical violent explosion resulting from conversion of a neutron star to a quark star}}
A '''quark-nova'''  is the hypothetical violent explosion resulting from the conversion of a [[Astronomy:Neutron star|neutron star]] to a [[Astronomy:Quark star|quark star]]. Analogous to a [[Astronomy:Supernova|supernova]] heralding the birth of a neutron star, a quark nova signals the creation of a quark star. The term quark-novae was coined in 2002 by Dr. Rachid Ouyed (currently at the University of Calgary, Canada)<ref>{{cite web|url=http://www.quarknova.ca/|title=Quark Nova Project|access-date=13 Sep 2018}}</ref> and Drs. J. Dey and M. Dey (Calcutta University, India).<ref>{{cite journal |title=Quark-Nova|author1=R. Ouyed |author2=J. Dey |author3=M. Dey |doi=10.1051/0004-6361:20020982 |journal=Astronomy and Astrophysics |volume=390|pages=L39–L42 |year=2002 |issue=3 |arxiv=astro-ph/0105109|bibcode = 2002A&A...390L..39O|s2cid=124427846 }}</ref>

== The nova process ==
When a neutron star spins down, it may convert to a quark star through a process known as [[Physics:Color confinement|quark deconfinement]]. The resultant star would have [[Physics:Quark matter|quark matter]] in its interior. The process would release immense amounts of energy, perhaps explaining the most energetic explosions in the universe; calculations have estimated that as much as 10<sup>46</sup> [[Joule|J]] could be released from the phase transition inside a neutron star.<ref>{{cite web|url=http://www.citebase.org/fulltext?format=application%2Fpdf&identifier=oai%3AarXiv.org%3Aastro-ph%2F0105109 |title=Theories of Quark-novae |access-date=11 Feb 2009 |url-status=unfit |archive-url=https://web.archive.org/web/20121007062931/http://www.citebase.org/fulltext?format=application%2Fpdf&identifier=oai%3AarXiv.org%3Aastro-ph%2F0105109 |archive-date=October 7, 2012 }}</ref> Quark-novae may be one cause of gamma ray bursts. According to Jaikumar ''et al.'',<ref>{{cite journal |title=Nucleosynthesis in neutron-rich ejecta from Quark-Novae |author1=Prashanth Jaikumar |author2=Meyer |author3=Kaori Otsuki |author4=Rachid Ouyed |doi=10.1051/0004-6361:20066593 |journal=Astronomy and Astrophysics |volume=471 |pages=227–236 |year=2007 |issue=1 |arxiv=nucl-th/0610013|bibcode = 2007A&A...471..227J |s2cid=119093518 }}</ref> they may also be involved in producing heavy elements such as [[Chemistry:Platinum|platinum]] through [[Physics:R-process|r-process nucleosynthesis]].

== Candidates ==
Rapidly spinning neutron stars with masses between 1.5 and 1.8 [[Astronomy:Solar mass|solar mass]]es are theoretically the best candidates for conversion due to spin down of the star within a Hubble time. This amounts to a small fraction of the projected neutron star population. A conservative estimate based on this, indicates that up to two quark-novae may occur in the [[Astronomy:Observable universe|observable universe]] each day.

Theoretically, quark stars would be radio-quiet, so radio-quiet neutron stars may be quark stars.

== Observations ==
Direct evidence for quark-novae is scant; however, recent observations of supernovae [[Astronomy:SN 2006gy|SN 2006gy]], [[Astronomy:SN 2005gj|SN 2005gj]] and [[Astronomy:SN 2005ap|SN 2005ap]] may point to their existence.<ref>[http://astronomynow.com/080604Secondsupernovaepointtoquarkstars.html Astronomy Now Online - Second Supernovae Point to Quark Stars]</ref><ref>{{cite journal|bibcode=2008MNRAS.387.1193L|author1=Leahy, Denis|author2=Ouyed, Rachid|doi=10.1111/j.1365-2966.2008.13312.x|year=2008|pages=1193|issue=3|volume=387|journal=[[Organization:Monthly Notices of the Royal Astronomical Society|Monthly Notices of the Royal Astronomical Society]] |title=Supernova SN2006gy as a first ever Quark Nova?|arxiv = 0708.1787 |s2cid=15696112}}</ref>

==See also==
* {{annotated link|Physics:QCD matter|aka=quark matter}}
* {{annotated link|Astronomy:SN 2006gy}}
* {{annotated link|Astronomy:SN 2005gj}}

==References==
{{Reflist}}

==External links==
*[http://ads.nao.ac.jp/abs/1994AstL...20..499M Quark-novae produce neutrino bursts, which can be detected by neutrino observatories]
*[http://www.spacedaily.com/reports/Quark_Stars_Could_Produce_Biggest_Bang.html Quark Stars Could Produce Biggest Bang] (SpaceDaily) June 7, 2006
*[https://web.archive.org/web/20131213213311/http://quarknova.ucalgary.ca/media/ Quark Nova Project animations] (University of Calgary)

{{supernovae}}

{{DEFAULTSORT:Quark-Nova}}
[[Category:Quark stars]]
[[Category:Supernovae]]
[[Category:Hypothetical astronomical objects]]

{{Sourceattribution|Quark-nova}}