Cygnus x-3
Encyclopedia
Cygnus X-3 is one of the stronger binary X-ray sources in the sky.
Classified as a microquasar, it is believed to be a compact object in a binary system which is pulling in a stream of gas from an ordinary star
companion.
It is observed in X rays, gamma rays, infrared, and radio, with an orbital periodicity of approximately 4.8 h, among the shortest known at the time of its discovery.
Although it is only the third brightest x-ray source in the constellation Cygnus
, after the more famous Cygnus X-1
, it is located about 37,000 light-years away.
It is heavily obscured by intervening interstellar gas and dust near the galactic plane, and
fainter than 23rd magnitude in the optical, but is easily observable in the J, H, & K near-infrared bands.
Taking its distance and extinction into account, it appears to be one of the two or three most intrinsically luminous
objects in the Galaxy.
It has also received attention because it is one of the few sources of ultra-high energy cosmic rays, with energies in the 100 - 1000 TeV
range. Its most unusual aspect is the production of anomalous cosmic ray events in a proton decay
detector deep in Minnesota's Soudan iron mine. These events have defied analysis and have led to questions about whether Cygnus X-3 is a standard neutron star
or perhaps something more exotic, like a star made of quarks.
Cygnus X-3 has distinguished itself by its intense X-ray emissions and by ultra-high energy cosmic rays. It also made astronomical headlines by a radio frequency
outburst in September 1972 which increased its radio frequency emissions a thousandfold. Since then it has had periodic
radio outbursts with a regular period of 367 days. These flares are of unknown origin, but they are exceedingly violent events. Naval Research Laboratory observations in October 1982 using the Very Large Array
detected the shock wave from a flare; it was expanding at roughly one-third the speed of light.
Cygnus X-3 has an orbital period about its companion of only 4.79 hours. Intriguing underground events in the SOUDAN experiment
in October 1985 included 60 anomalous muon events in a 3° cone around Cygnus X-3 with a precise period of 4.79 hours.
If the association with Cygnus X-3 is confirmed, these events must either be due to neutrino
s or some other very low-rest-mass, high-energy neutral particle of unknown nature, yet capable of producing muon
s via secondary interactions.
Infrequent gamma ray
flares from Cygnus X-3 with energies around 100 million EV were detected in 2009 by the Fermi Gamma-ray Space Telescope and by the AGILE satellite. The intensity of these gamma ray outbursts varies at the same 4.8-hour orbital rate as the X-ray emissions, and they occur a few days before the onset of extremely energetic radio jets.
Classified as a microquasar, it is believed to be a compact object in a binary system which is pulling in a stream of gas from an ordinary 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...
companion.
It is observed in X rays, gamma rays, infrared, and radio, with an orbital periodicity of approximately 4.8 h, among the shortest known at the time of its discovery.
Although it is only the third brightest x-ray source in the constellation Cygnus
Cygnus (constellation)
Cygnus is a northern constellation lying on the plane of the Milky Way. Its name is the Latinized Hellenic word for swan. One of the most recognizable constellations of the northern summer and autumn, it features a prominent asterism known as the Northern Cross...
, after the more famous Cygnus X-1
Cygnus X-1
Cygnus X-1 is a well-known galactic X-ray source in the constellation Cygnus. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources seen from Earth, producing a peak X-ray flux density of 2.3 Wm−2Hz−1...
, it is located about 37,000 light-years away.
It is heavily obscured by intervening interstellar gas and dust near the galactic plane, and
fainter than 23rd magnitude in the optical, but is easily observable in the J, H, & K near-infrared bands.
Taking its distance and extinction into account, it appears to be one of the two or three most intrinsically luminous
Luminosity
Luminosity is a measurement of brightness.-In photometry and color imaging:In photometry, luminosity is sometimes incorrectly used to refer to luminance, which is the density of luminous intensity in a given direction. The SI unit for luminance is candela per square metre.The luminosity function...
objects in the Galaxy.
It has also received attention because it is one of the few sources of ultra-high energy cosmic rays, with energies in the 100 - 1000 TeV
TEV
TEV may refer to:* TeV, or teraelectronvolt, a measure of energy* Total Enterprise Value, a financial measure* Total Economic Value, an economic measure* Tobacco etch virus, a plant pathogenic virus of the family Potyviridae....
range. Its most unusual aspect is the production of anomalous cosmic ray events in a proton decay
Proton decay
In particle physics, proton decay is a hypothetical form of radioactive decay in which the proton decays into lighter subatomic particles, such as a neutral pion and a positron...
detector deep in Minnesota's Soudan iron mine. These events have defied analysis and have led to questions about whether Cygnus X-3 is a standard neutron star
Neutron star
A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with a slightly larger...
or perhaps something more exotic, like a star made of quarks.
Cygnus X-3 has distinguished itself by its intense X-ray emissions and by ultra-high energy cosmic rays. It also made astronomical headlines by a radio frequency
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
outburst in September 1972 which increased its radio frequency emissions a thousandfold. Since then it has had periodic
Frequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...
radio outbursts with a regular period of 367 days. These flares are of unknown origin, but they are exceedingly violent events. Naval Research Laboratory observations in October 1982 using the Very Large Array
Very Large Array
The Very Large Array is a radio astronomy observatory located on the Plains of San Agustin, between the towns of Magdalena and Datil, some fifty miles west of Socorro, New Mexico, USA...
detected the shock wave from a flare; it was expanding at roughly one-third the speed of light.
Cygnus X-3 has an orbital period about its companion of only 4.79 hours. Intriguing underground events in the SOUDAN experiment
Soudan 1
Soudan 1 was a particle detector located in the Soudan Mine in Northern Minnesota, United States. It was a 30 ton iron tracking calorimeter whose primary purpose was to search for proton decay. It set a lower limit on the lifetime of the proton of 1.6×1030 years as well as upper limits on the...
in October 1985 included 60 anomalous muon events in a 3° cone around Cygnus X-3 with a precise period of 4.79 hours.
If the association with Cygnus X-3 is confirmed, these events must either be due to neutrino
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...
s or some other very low-rest-mass, high-energy neutral particle of unknown nature, yet capable of producing muon
Muon
The muon |mu]] used to represent it) is an elementary particle similar to the electron, with a unitary negative electric charge and a spin of ½. Together with the electron, the tau, and the three neutrinos, it is classified as a lepton...
s via secondary interactions.
Infrequent gamma ray
Gamma ray
Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as γ, is electromagnetic radiation of high frequency . Gamma rays are usually naturally produced on Earth by decay of high energy states in atomic nuclei...
flares from Cygnus X-3 with energies around 100 million EV were detected in 2009 by the Fermi Gamma-ray Space Telescope and by the AGILE satellite. The intensity of these gamma ray outbursts varies at the same 4.8-hour orbital rate as the X-ray emissions, and they occur a few days before the onset of extremely energetic radio jets.