View source for Physics:Supernova Early Warning System

The '''SuperNova Early Warning System (SNEWS)''' is a network of [[Physics:Neutrino|neutrino]] detectors designed to give early warning to astronomers in the event of a [[Astronomy:Supernova|supernova]] in the [[Astronomy:Milky Way|Milky Way]], our home galaxy, or in a nearby galaxy such as the [[Astronomy:Large Magellanic Cloud|Large Magellanic Cloud]] or the Canis Major Dwarf Galaxy.
{{As of|2018|05}}, SNEWS has not issued any supernova alerts, as the [[Astronomy:G1.9+0.3|most recent known supernova remnant]] in the Milky Way was around the turn of the 20th century, and the most recent supernova confirmed to have been observed was [[Astronomy:Kepler's Supernova|Kepler's Supernova]] in 1604.

Powerful bursts of electron neutrinos (ν<sub>e</sub>) with typical energies of the order of 10 MeV and duration of the order of 10 seconds are produced in the [[Astronomy:Solar core|core]] of a [[Astronomy:Red giant|red giant]] star as it collapses on itself via the "neutronization" reaction, i.e. fusion of protons and electrons into neutrons: pe<sup>&minus;</sup>→nν<sub>e</sub>. It is expected that the neutrinos are emitted well before the light from the supernova peaks, so in principle neutrino detectors could give advance warning to astronomers that a supernova has occurred and may soon be visible.  The neutrino pulse from [[Astronomy:SN 1987A|supernova 1987A]] arrived 3 hours before the associated photons – but SNEWS was not yet active and it was not recognised as a supernova event until after the photons arrived. However, SNEWS is not able to give advance warning of a [[Astronomy:Type Ia supernova|type Ia supernova]], as they are not expected to produce significant numbers of neutrinos. Type Ia supernovae, caused by a runaway nuclear fusion reaction in a [[Astronomy:White dwarf|white dwarf]] star, are thought to account for roughly one-third of all supernovae.<ref>{{cite journal |last1=Adams |first1=Scott |last2=et |first2=al |title=Observing the Next Galactic Supernova |journal=Astrophysical Journal |date=2013 |volume=778 |issue=2 |page=164 |doi=10.1088/0004-637X/778/2/164 |arxiv=1306.0559 |ref=3|bibcode=2013ApJ...778..164A }}</ref>

There are currently seven neutrino detector members of SNEWS: [[Astronomy:Borexino|Borexino]], [[Physics:Daya Bay Reactor Neutrino Experiment|Daya Bay]], KamLAND, HALO, [[Astronomy:IceCube Neutrino Observatory|IceCube]], [[Physics:Large Volume Detector|LVD]], and [[Astronomy:Super-Kamiokande|Super-Kamiokande]].<ref>{{cite web|url=http://snews.bnl.gov/news.html|title=SNEWS News|publisher=Brookhaven National Laboratory|year=2015|accessdate=2015-12-06}}</ref>  SNEWS began operation prior to 2004, with three members (Super-Kamiokande, LVD, and SNO). The [[Astronomy:Sudbury Neutrino Observatory|Sudbury Neutrino Observatory]] is no longer active as it is being upgraded to its successor program [[Astronomy:SNO+|SNO+]].

The detectors send reports of a possible supernova to a computer at [[Organization:Brookhaven National Laboratory|Brookhaven National Laboratory]] to identify a supernova. If the SNEWS computer identifies signals from two detectors within 10 seconds, the computer will send a supernova alert to observatories around the world to study the supernova.<ref>{{Cite web |title=Physicists Eagerly Await Neutrinos from the Next Nearby Supernova [Excerpt] |url=http://www.scientificamerican.com/article/physicists-eagerly-await-neutrinos-from-the-next-nearby-supernova |accessdate=2015-10-07 |first=Ray |last=Jayawardhana}}</ref> The SNEWS mailing list is open-subscription, and the general public is allowed to sign up; however, the SNEWS collaboration encourages amateur astronomers to instead use Sky and Telescope magazine's AstroAlert service, which is linked to SNEWS.

== See also ==
* [[Astronomy:Near-Earth supernova|Near-Earth supernova]]
* [[Astronomy:History of supernova observation|History of supernova observation]]
* Timeline of white dwarfs, neutron stars, and supernovae
* [[Physics:Supernova nucleosynthesis|Supernova nucleosynthesis]]
* [[Physics:Neutrino#Supernova neutrinos|Supernova neutrinos]]

==References==
{{Reflist}}

== External links ==
* {{cite journal |last1=Antonioli |first1=P. |title=SNEWS: the SuperNova Early Warning System|journal=[[Physics:New Journal of Physics|New Journal of Physics]]|volume=6|pages=114–114|year=2004|doi=10.1088/1367-2630/6/1/114|arxiv = astro-ph/0406214 |bibcode = 2004NJPh....6..114A |display-authors=0}}
* Francis Reddy, "[http://www.astronomy.com/asy/default.aspx?c=a&id=3232 Time for SNEWS]", ''Astronomy'' 3 June 2005
* [http://broadband.wgbh.org/nova/rss/nova-podcast-pb.xml NOVA podcast about SNEWS] ([http://broadband.wgbh.org/nova/rss/media/nova-a-20060216.mp3 the same in MP3 format])
* {{Cite web |url=http://sites.duke.edu/dukeresearch/2014/01/22/supernova-explosion-in-m82-exciting-but-no-neutrinos/ |title=Supernova Explosion in M82: Exciting, but No Neutrinos |first=Erin |last=Weeks |date=22 January 2014 |website=Duke University Research Blog |accessdate=2015-12-06}}

{{neutrino detectors}}
{{supernovae}}

[[Category:Particle experiments]]

{{Sourceattribution|Supernova Early Warning System|1}}