Supernova Early Warning System
Encyclopedia
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
galaxy
or a nearby galaxy such as the Large Magellanic Cloud
or the Canis Major Dwarf Galaxy
. Enormous numbers of neutrinos are produced in the core
of a red giant
star
as it collapses on itself. In the current model 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 supernova 1987A
was detected 3 hours before the photons but this detection occurred before SNEWS was active.
The current members of SNEWS are Borexino
, Super-Kamiokande
, LVD
, SNO
and IceCube. SNO is not currently active as it is being upgraded to its successor program SNO+
.
, SNEWS has not issued any SN alerts.
Neutrino
A neutrino is an electrically neutral, weakly interacting elementary subatomic particle with a half-integer spin, chirality and a disputed but small non-zero mass. It is able to pass through ordinary matter almost unaffected...
detectors designed to give early warning to astronomers in the event of a supernova
Supernova
A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...
in the Milky Way
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...
galaxy
Galaxy
A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...
or a nearby galaxy such as the Large Magellanic Cloud
Large Magellanic Cloud
The Large Magellanic Cloud is a nearby irregular galaxy, and is a satellite of the Milky Way. At a distance of slightly less than 50 kiloparsecs , the LMC is the third closest galaxy to the Milky Way, with the Sagittarius Dwarf Spheroidal and Canis Major Dwarf Galaxy lying closer to the center...
or the Canis Major Dwarf Galaxy
Canis Major Dwarf Galaxy
The Canis Major Dwarf Galaxy is located in the same part of the sky as the constellation Canis Major. The galaxy contains a relatively high percentage of red giant stars, and is thought to contain an estimated one billion stars in all....
. Enormous numbers of neutrinos are produced in the core
Solar core
The core of the Sun is considered to extend from the center to about 0.2 to 0.25 solar radius. It is the hottest part of the Sun and of the Solar System. It has a density of up to 150 g/cm³ and a temperature of close to 15,000,000 kelvin...
of a red giant
Red giant
A red giant is a luminous giant star of low or intermediate mass in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius immense and the surface temperature low, somewhere from 5,000 K and lower...
star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
as it collapses on itself. In the current model 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 supernova 1987A
SN 1987A
SN 1987A was a supernova in the outskirts of the Tarantula Nebula in the Large Magellanic Cloud, a nearby dwarf galaxy. It occurred approximately 51.4 kiloparsecs from Earth, approximately 168,000 light-years, close enough that it was visible to the naked eye. It could be seen from the Southern...
was detected 3 hours before the photons but this detection occurred before SNEWS was active.
The current members of SNEWS are Borexino
Borexino
Borexino is a particle physics experiment to study low energy solar neutrinos. The primary aim of the experiment is to make a precise measurement of the beryllium-7 neutrino flux from the sun and comparing it to the Standard solar model prediction...
, Super-Kamiokande
Super-Kamiokande
Super-Kamiokande is a neutrino observatory which is under Mount Kamioka near the city of Hida, Gifu Prefecture, Japan...
, LVD
Large Volume Detector
The Large Volume Detector is a particle physics experiment situated in the Gran Sasso laboratory in Italy and is operated by the Italian Institute of Nuclear Physics. It has been in operation since June 1992, and is a member of the Supernova Early Warning System. Among other work, the detector...
, SNO
Sudbury Neutrino Observatory
The Sudbury Neutrino Observatory is a neutrino observatory located 6,800 feet underground in Vale Inco's Creighton Mine in Sudbury, Ontario, Canada. The detector was designed to detect solar neutrinos through their interactions with a large tank of heavy water. The detector turned on in May 1999,...
and IceCube. SNO is not currently active as it is being upgraded to its successor program SNO+
SNO+
SNO+ is an underground physics experiment under construction that makes use of the equipment already installed underground for the former Sudbury Neutrino Observatory experiment at SNOLAB...
.
, SNEWS has not issued any SN alerts.
See also
- Near-Earth supernovaNear-Earth supernovaA near-Earth supernova is an explosion resulting from the death of a star that occurs close enough to the Earth to have noticeable effects on its biosphere.-Effects on the planet:...
- History of supernova observationHistory of supernova observationThe known history of supernova observation goes back to 185 CE, when supernova SN 185 appeared, the oldest appearance of a supernova recorded by humankind...
- Timeline of white dwarfs, neutron stars, and supernovaeTimeline of white dwarfs, neutron stars, and supernovaeTimeline of white dwarfs, neutron stars, and supernovaeNote that this list is mainly about the development of knowledge, but also about some supernovae taking place. For a separate list of the latter, see the article List of supernovae...
- Supernova nucleosynthesisSupernova nucleosynthesisSupernova nucleosynthesis is the production of new chemical elements inside supernovae. It occurs primarily due to explosive nucleosynthesis during explosive oxygen burning and silicon burning...
- Supernova neutrinos