SHGb02+14a is an

astronomical radio source An astronomical radio source is an object in outer space that emits strong radio waves. Radio emission comes from a wide variety of sources. Such objects are among the most extreme and energetic physical processes in the universe. History In 1932, ...

and a candidate in the Search for Extra-Terrestrial Intelligence (SETI), discovered in March 2003 by SETI@home and announced in ''

New Scientist ''New Scientist'' is a magazine covering all aspects of science and technology. Based in London, it publishes weekly English-language editions in the United Kingdom, the United States and Australia. An editorially separate organisation publishe ...

'' on September 1, 2004.

Observation

The source was originally detected by Oliver Voelker of Logpoint in Nuremberg, Germany and Nate Collins of Farin and Associates in Wisconsin, USA using the giant

Arecibo Telescope The Arecibo Telescope was a spherical reflector radio telescope built into a natural sinkhole at the Arecibo Observatory located near Arecibo, Puerto Rico. A cable-mount steerable receiver and several radar transmitters for emitting signals wer ...

in Puerto Rico. It was observed three times (for a total of about one minute) at a

frequency Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...

of about 1420

MHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one he ...

, one of the frequencies in the

waterhole A waterhole is a depression in the ground in which water can collect, or a more permanent pool in the bed of an ephemeral river. Waterhole or water hole may refer to: * Water hole (radio), an especially quiet region of the electromagnetic spect ...

region, which is theorized to be a good candidate for frequencies used by

extraterrestrial intelligence Extraterrestrial intelligence (often abbreviated ETI) refers to hypothetical intelligent extraterrestrial life. The question of whether other inhabited worlds might exist has been debated since ancient times. The modern form of the concept emerged ...

to broadcast contact signals. There are a number of puzzling features of this candidate, which have led to a large amount of skepticism. The source is located between the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Pisces Pisces may refer to: * Pisces, an obsolete (because of land vertebrates) taxonomic superclass including all fish * Pisces (astrology), an astrological sign * Pisces (constellation), a constellation **Pisces Overdensity, an overdensity of stars in ...

and

Aries Aries may refer to: *Aries (astrology), an astrological sign *Aries (constellation), a constellation of stars in the zodiac Arts, entertainment and media * ''Aries'' (album), by Luis Miguel, 1993 * ''Aries'' (EP), by Alice Chater, 2020 * "Aries" ...

, a direction in which no

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

s are observed within 1000

light year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s from

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

. It is also a very weak signal. The frequency of the signal has a rapid

drift Drift or Drifts may refer to: Geography * Drift or ford (crossing) of a river * Drift, Kentucky, unincorporated community in the United States * In Cornwall, England: ** Drift, Cornwall, village ** Drift Reservoir, associated with the village ...

, changing by between 8 and 37 hertz per second. If the cause is

Doppler shift The Doppler effect or Doppler shift (or simply Doppler, when in context) is the change in frequency of a wave in relation to an observer who is moving relative to the wave source. It is named after the Austrian physicist Christian Doppler, who d ...

, it would indicate emission from a

planet A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a you ...

rotating nearly 40 times faster on its axis than the Earth. Each time the signal was detected, it was again at about 1420 MHz, the original frequency before any drift. There are a number of potential explanations for this signal. SETI@home has denied media reports of a likely extraterrestrial intelligence signal. It could be an artifact of random chance,

cosmic noise Cosmic noise, also known as galactic radio noise, is not actually sound, but a physical phenomenon derived from outside of the Earth's atmosphere. It can be detected through a radio receiver, which is an electronic device that receives radio waves ...

or even a glitch in the technology.

Star field

The region is unusually devoid of any nearby stars. The closest star systems in the approximate region of the signal include the binary star G 73-11A and B, which are 106.1

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s from the Sun, although the unrelated star G 73-10 is only 108.7 light-years away, less than three light-years from G 73-11A and B. All of these stars are

red dwarf ''Red Dwarf'' is a British science fiction comedy franchise created by Rob Grant and Doug Naylor, which primarily consists of a television sitcom that aired on BBC Two between 1988 and 1999, and on Dave since 2009, gaining a cult following. T ...

s much less massive than the Sun. The much nearer star, L 1159-16, which is one of the nearest 40 stars to the Sun, is near the signal's position, but its proximity is likely coincidental.

References and notes

External links

Signal Candidate SHGb02+14a
* SETI@home (classic)'

{{DEFAULTSORT:Shgb02+14a 2003 in science Astronomical radio sources Radio spectrum Search for extraterrestrial intelligence

Observation

Star field

See also

References and notes

External links