The Baksan Neutrino Observatory (BNO; Baksan is sometimes spelled Baxan) is a scientific laboratory of INR RAS located in the

Baksan River The Baksan () is a river in Kabardino-Balkaria in Russia. It flows east northeast and joins the Malka just before that river joins the northwest bend of the Terek. The Baksan is long, with a drainage basin of . Course The Baksan River is a 169 ...

gorge in the

Caucasus The Caucasus () or Caucasia (), is a region spanning Eastern Europe and Western Asia. It is situated between the Black Sea and the Caspian Sea, comprising parts of Southern Russia, Georgia, Armenia, and Azerbaijan. The Caucasus Mountains, i ...

mountains in

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

. Cleared for building in 1967, it started operations in 1977, becoming the first such

neutrino A neutrino ( ; denoted by the Greek letter ) is an elementary particle that interacts via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass is so small ('' -ino'') that i ...

observatory in the

USSR The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

. It consists of the Baksan Underground Scintillation Telescope (BUST), located below the surface, the

gallium Gallium is a chemical element; it has Chemical symbol, symbol Ga and atomic number 31. Discovered by the French chemist Paul-Émile Lecoq de Boisbaudran in 1875, elemental gallium is a soft, silvery metal at standard temperature and pressure. ...

–

germanium Germanium is a chemical element; it has Symbol (chemistry), symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid or a nonmetal in the carbon group that is chemically ...

neutrino telescope (

Soviet–American Gallium Experiment SAGE (Soviet–American Gallium Experiment, or sometimes Russian-American Gallium Experiment) is a collaborative experiment devised by several prominent physicists to measure the solar neutrino flux. The experiment SAGE was devised to measure the ...

, SAGE) located 4,700 m.w.e. deep (2,100 meters) as well as a number of ground facilities. The Baksan Experiment on Sterile Transitions (

BEST Best or The Best may refer to: People * Best (surname), people with the surname Best * Best (footballer, born 1968), retired Portuguese footballer Companies and organizations * Best & Co., an 1879–1971 clothing chain * Best Lock Corporatio ...

) is currently (2019) being conducted at Baksan with aims of understanding

sterile neutrinos Sterile or sterility may refer to: *Asepsis, a state of being free from biological contaminants * Sterile (archaeology), a sediment deposit which contains no evidence of human activity *Sterilization (microbiology), any process that eliminates or ...

. The laboratory itself is located in a 4,000 meter long horizontal tunnel mined specifically for this purpose; this is in contrast to most underground physics laboratories which are placed in abandoned or still in-use mines. The entrance of the tunnel is at a valley at 1,700 meters high from sea level and the tunnel itself is located under the 4,000 meters tall mountain Mount Andyrchi. A small town named Neutrino was built in the valley, in conjunction with the construction of the laboratory, to house the scientists and their families. The first experiment undertaken at BNO was not underground; it was the Carpet () air-shower cosmic ray experiment in 1973. Carpet relied on liquid scintillator detectors to study cosmic ray air showers. Carpet also made discoveries of astrophysical importance, such as detecting a giant flare in the

Crab Nebula The Crab Nebula (catalogue designations M1, NGC 1952, Taurus A) is a supernova remnant and pulsar wind nebula in the constellation of Taurus (constellation), Taurus. The common name comes from a drawing that somewhat resembled a crab with arm ...

in 1989. The Carpet cosmic ray experiment continues as of 2017, and it is being upgraded to use a

gamma-ray telescope Gamma-ray astronomy is a subfield of astronomy where scientists observe and study celestial objects and phenomena in outer space which emit cosmic electromagnetic radiation in the form of gamma rays,Astronomical literature generally hyphenat ...

. Further upgrades are also planned. The first underground experiment, the BUST, started in 1977. It is located 550 meters from the tunnel entrance. It detected

neutrinos A neutrino ( ; denoted by the Greek letter ) is an elementary particle that interacts via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass is so small ('' -ino'') that it ...

from the

SN1987A SN 1987A was a Type II supernova in the Large Magellanic Cloud, a dwarf satellite galaxy of the Milky Way. It occurred approximately from Earth and was the closest observed supernova since Kepler's Supernova in 1604. Light and neutrinos f ...

supernova. It continues to operate (as of 2017). The next experiment at BNO was the Gallium-Germanium Neutrino Telescope (GGNT) as part of the SAGE experiment. It is located 3,500 meters from the tunnel entrance. It started in 1986 and was still in operation as of 2017. In addition to the big experiments BUST and SAGE, a number of smaller experiments that benefit from the low-background location have taken place at BNO; for example, the isotopic composition of the lunar samples brought by

Luna 16 ''Luna 16'' was an uncrewed 1970 space mission, part of the Soviet Luna program. It was the first robotic probe to land on the Moon and return a sample of lunar soil to Earth. The 101 grams (3.56 ounces) sample was returned from Mare Fecundit ...

Luna 20 ''Luna 20'' was the second of three successful Soviet lunar sample return missions. It was flown as part of the Luna program as a robotic competitor to the six successful Apollo lunar sample return missions. ''Luna 20'' was placed in an int ...

and

Luna 24 ''Luna 24'' was a robotic probe of the Soviet Union's Luna programme. The 24th mission of the Luna series of spacecraft, the mission of the ''Luna 24'' probe was the third Soviet mission to return lunar soil samples from the Moon (the first t ...

spacecraft was measured in BNO. BNO is also home to the Andyrchi air-shower array, located on the surface above BUST in the mountain slope. The array and BUST work in concert. BNO hosts also a small gravitational-wave detector, OGRAN. OGRAN would be capable of registering a galactic supernova, should one occur in the Milky Way. The BNO-observatory is planning (as of 2021) a new major detector, the Baksan Large Underground Scintillation Telescope (BLUST). This detector would consist of huge (10 kilotonnes) amounts of liquid scintillator. It would be located at the end of the laboratory tunnel. It would mainly detect neutrinos. As of 2017, the director of the observatory is Valery Kuzminov.

References

External links

*
Photographs of the Baksan Observatory via englishrussia.com

{{authority control 1977 establishments in Russia Neutrino observatories Research institutes in Russia Astronomical observatories built in the Soviet Union Research institutes in the Soviet Union Underground laboratories

See also

References

External links