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 SETI@home ("SETI at home") is a project of the Berkeley SETI Research Center to analyze radio signals with the aim of Search for extraterrestrial intelligence, searching for signs of extraterrestrial intelligence. Until March 2020, it was run ...

and announced in ''

New Scientist ''New Scientist'' is a popular science 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 organ ...

'' 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 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. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio ...

of about 1420

MHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base u ...

, one of the frequencies in the waterhole region, which is theorized to be a good candidate for frequencies used by extraterrestrial intelligence 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 first constellati ...

s Pisces and Aries, a direction in which no

star A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sk ...

s are observed within 1000

light year A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distance, astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by t ...

s from

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

. It is also a very weak signal. The frequency of the signal has a rapid drift, changing by between 8 and 37 hertz per second. If the cause is

Doppler shift The Doppler effect (also Doppler shift) is the change in the frequency of a wave in relation to an observer who is moving relative to the source of the wave. The ''Doppler effect'' is named after the physicist Christian Doppler, who described t ...

, it would indicate emission from a

planet A planet is a large, Hydrostatic equilibrium, rounded Astronomical object, astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. The Solar System has eight planets b ...

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.

has denied media reports of a likely extraterrestrial intelligence signal. It could be an artifact of random chance, cosmic noise 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 (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by the International Astr ...

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 A red dwarf is the smallest kind of star on the main sequence. Red dwarfs are by far the most common type of fusing star in the Milky Way, at least in the neighborhood of the Sun. However, due to their low luminosity, individual red dwarfs are ...

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