CTA 102, also known by its

B1950 In astronomy, an equinox is either of two places on the celestial sphere at which the ecliptic intersects the celestial equator. Although there are two such intersections, the equinox associated with the Sun's ascending node is used as the con ...

coordinates as 2230+114 (QSR B2230+114) and its

J2000 In astronomy, an epoch or reference epoch is a instant, moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a Astronomical object, celestial body, ...

coordinates as J2232+1143 (QSO J2232+1143), is a

blazar A blazar is an active galactic nucleus (AGN) with a relativistic jet (a jet composed of ionized matter traveling at nearly the speed of light) directed very nearly towards an observer. Relativistic beaming of electromagnetic radiation from the ...

-type

quasar A quasar is an extremely Luminosity, luminous active galactic nucleus (AGN). It is pronounced , and sometimes known as a quasi-stellar object, abbreviated QSO. This emission from a galaxy nucleus is powered by a supermassive black hole with a m ...

discovered in the early 1960s by a radio survey carried out by the

California Institute of Technology The California Institute of Technology (branded as Caltech or CIT)The university itself only spells its short form as "Caltech"; the institution considers other spellings such a"Cal Tech" and "CalTech" incorrect. The institute is also occasional ...

. It has been observed by a large range of instruments since its discovery, including

WMAP The Wilkinson Microwave Anisotropy Probe (WMAP), originally known as the Microwave Anisotropy Probe (MAP and Explorer 80), was a NASA spacecraft operating from 2001 to 2010 which measured temperature differences across the sky in the cosmic mic ...

EGRET Egrets ( ) are herons, generally long-legged wading birds, that have white or buff plumage, developing fine plumes (usually milky white) during the breeding season. Egrets are not a biologically distinct group from herons and have the same build ...

GALEX Galaxy Evolution Explorer (GALEX or Explorer 83 or SMEX-7) was a NASA orbiting space telescope designed to observe the universe in ultraviolet wavelengths to measure the history of star formation in the universe. In addition to paving the way ...

, VSOP and

Parkes Parkes may refer to: * Sir Henry Parkes (1815–1896), Australian politician, one of the earliest and most prominent advocates for Australian federation Named for Henry Parkes * Parkes, New South Wales, a regional town * Parkes Observatory, a radi ...

, and has been regularly imaged by the

Very Long Baseline Array The Very Long Baseline Array (VLBA) is a system of ten radio telescopes which are operated remotely from their Array Operations Center located in Socorro, New Mexico, as a part of the National Radio Astronomy Observatory (NRAO). These ten radi ...

since 1995. It has also been detected in

gamma rays A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically ...

, and a gamma-ray flare has been detected from it. In 1963

Nikolai Kardashev Nikolai Semyonovich Kardashev ( rus, Никола́й Семёнович Кардашёв, p=nʲɪkɐˈlaj sʲɪˈmʲɵnəvʲɪtɕ kərdɐˈʂof; 25 April 1932 – 3 August 2019) was a Soviet Union, Soviet and Russian Astrophysics, astrophysicis ...

proposed that the then-unidentified radio source could be evidence of a Type II or III extraterrestrial civilization on the

Kardashev scale The Kardashev scale (Russian: Шкала Кардашева, ''Shkala Kardasheva'') is a method of measuring a civilization's level of technological advancement based on the amount of energy it is able to use. The measure was proposed by Sovie ...

. Follow-up observations were announced in 1965 by Gennady Sholomitskii, who found that the object's radio emission was varying; a public announcement of these results on April 12, 1965, caused a worldwide sensation. The idea that the emission was caused by a civilization was rejected when the radio source was later identified as one of the many varieties of a

. CTA 102 is one of the two great false alarms in the history of the search for extra-terrestrial life, the other being the discovery of

pulsars A pulsar (from ''pulsating radio source'') is a highly magnetized rotating neutron star that emits beams of electromagnetic radiation out of its magnetic poles. This radiation can be observed only when a beam of emission is pointing toward Ea ...

, specifically

PSR B1919+21 PSR B1919+21 is a pulsar with a period of 1.3373 seconds and a pulse width of 0.04 seconds. Discovered by Jocelyn Bell Burnell on 28 November 1967, it is the first discovered radio pulsar. The power and regularity of the signals wer ...

, which are rotating neutron stars. The American

folk rock Folk rock is a hybrid music genre that combines the elements of folk and rock music, which arose in the United States, Canada, and the United Kingdom in the mid-1960s. In the U.S., folk rock emerged from the folk music revival. Performers suc ...

band

The Byrds The Byrds () were an American rock band formed in Los Angeles, California, in 1964. The band underwent multiple lineup changes throughout its existence, with frontman Roger McGuinn (known as Jim McGuinn until mid-1967) remaining the sole cons ...

whimsically reflected the original view that CTA-102 was a sign of extraterrestrial intelligence in their song "C.T.A.-102" from their 1967 album ''

Younger Than Yesterday ''Younger Than Yesterday'' is the fourth studio album by the American rock band the Byrds and was released on February 6, 1967 on Columbia Records. It saw the band continuing to integrate elements of psychedelia and jazz into their music, a proce ...

''. In late 2016 CTA 102, usually glowing around

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

+17, had a bright outburst in visible light to magnitude +11 (~250 times brighter than usual). This likely was the most luminous

state ever observed, with an

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse Logarithmic scale, logarithmic Magnitude (astronomy), astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent mag ...

in excess of -32. A new outburst began in December 2017, with increased gamma-ray and optical activity. As of 22 December 2017, it has reached magnitude +14.

References

{{Extraterrestrial life Search for extraterrestrial intelligence Quasars Pegasus (constellation)

See also

References