The SuperNova Early Warning System (SNEWS) is a network of neutrino detectors designed to give early warning to astronomers in the event of a supernova in the Milky Way, our home galaxy, or in a nearby galaxy such as the Large Magellanic Cloud or the Canis Major Dwarf Galaxy.
As of March 2021[update],[1] SNEWS has not issued any supernova alerts. This is unsurprising, as supernovae appear to be rare: the most recent known supernova remnant in the Milky Way was around the turn of the 20th century, and the most recent Milky Way supernova confirmed to have been observed was Kepler's Supernova in 1604.
SNEWS 2.0
editIn June 2019 a "SNEWS 2.0" workshop was held at Laurentian University of Sudbury in Canada, focused on plans for an update of SNEWS.[1][2] As the result, an upgraded system was devised under the name "SNEWS 2.0".[3][4]
Neutrino detection
editPowerful bursts of electron neutrinos (νe) with typical energies of the order of 10 MeV and duration of the order of 10 seconds are produced in the core of a red giant star as it collapses on itself via the "neutronization" reaction, i.e. fusion of protons and electrons into neutrons and neutrinos: p + e− → n + νe. It is expected that the neutrinos are emitted well before the light from the supernova peaks, so in principle neutrino detectors could give warning to astronomers that a supernova has occurred and may soon be visible. The neutrino pulse from 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.
Directional precision of approximately 5° is expected.[5] SNEWS is not able to give warning of a 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 white dwarf star, are thought to account for roughly one-third of all supernovae.[6]
There are currently seven neutrino detector members of SNEWS: Borexino, Daya Bay, KamLAND, HALO, IceCube, LVD, and Super-Kamiokande.[7] SNEWS began operation prior to 2004, with three members (Super-Kamiokande, LVD, and SNO). The Sudbury Neutrino Observatory is no longer active as it is being upgraded to its successor program SNO+.
The detectors send reports of a possible supernova to a computer at 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.[8] 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
editReferences
edit- ^ a b Kharusi, S. Al; BenZvi, S. Y.; Bobowski, J. S.; Bonivento, W.; Brdar, V.; Brunner, T.; Caden, E.; Clark, M.; Coleiro, A.; Colomer-Molla, M.; Crespo-Anadón, J. I.; Depoian, A.; Dornic, D.; Fischer, V.; Franco, D. (2021-03-15). "SNEWS 2.0: a next-generation supernova early warning system for multi-messenger astronomy". New Journal of Physics. 23 (3): 031201. arXiv:2011.00035. Bibcode:2021NJPh...23c1201A. doi:10.1088/1367-2630/abde33. ISSN 1367-2630.
- ^ "SNEWS 2.0 Workshop". Retrieved 2024-01-06.
- ^ Riordon, James. "New Supernova Alert System Promises Early Access to Spectacles in Space". Scientific American. Retrieved 2024-01-06.
- ^ Magazine, Smithsonian; Falk, Dan (2022-08-02). "When Will the Next Supernova in Our Galaxy Occur?". Smithsonian Magazine. Retrieved 2024-01-06.
- ^ Murphy, A. St. J. (2000). "SNEWS: The Supernova Early Warning System". Journal of the American Association of Variable Star Observers. 29 (1): 31. Bibcode:2000JAVSO..29...31M. Retrieved 2020-11-16.
- ^ Adams, Scott; et, al (2013). "Observing the Next Galactic Supernova". Astrophysical Journal. 778 (2): 164. arXiv:1306.0559. Bibcode:2013ApJ...778..164A. doi:10.1088/0004-637X/778/2/164. S2CID 119292900.
- ^ "SNEWS". Brookhaven National Laboratory. 2015. Retrieved 2015-12-06.
- ^ Jayawardhana, Ray (2013). "Physicists Eagerly Await Neutrinos from the Next Nearby Supernova [Excerpt]". Scientific American. 309 (6): 68–73. doi:10.1038/scientificamerican1213-68. PMID 24383367.
External links
edit- Official website of SNEWS 2.0
- Official website of SNEWS
- Antonioli, P.; et al. (2004). "SNEWS: the SuperNova Early Warning System". New Journal of Physics. 6: 114. arXiv:astro-ph/0406214. Bibcode:2004NJPh....6..114A. doi:10.1088/1367-2630/6/1/114. S2CID 119431247.
- Francis Reddy, "Time for SNEWS", Astronomy 3 June 2005
- NOVA podcast about SNEWS Archived 2006-04-09 at the Wayback Machine (the same in MP3 format[permanent dead link])
- Weeks, Erin (22 January 2014). "Supernova Explosion in M82: Exciting, but No Neutrinos". Duke University Research Blog. Retrieved 2015-12-06.