HD 164595 is a G-type star located in the constellation of

Hercules Hercules (, ) is the Roman equivalent of the Greek divine hero Heracles, son of Jupiter and the mortal Alcmena. In classical mythology, Hercules is famous for his strength and for his numerous far-ranging adventures. The Romans adapted the ...

, from Earth that is notably similar to the Sun. With an

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's ...

of 7.075, the star can be found with binoculars or a small telescope in the constellation

. The star has the same stellar classification as the Sun: G2V. It has a similar temperature, at compared with for the Sun. It has a lower logarithm of metallicity ratio, at −0.06 compared with 0.00, and a slightly younger age, at 4.5 versus 4.6

billion years A billion years or giga-annum (109 years) is a unit of time on the petasecond scale, more precisely equal to seconds (or simply 1,000,000,000 years). It is sometimes abbreviated Gy, Ga ("giga-annum"), Byr and variants. The abbreviations Gya or ...

Planetary system

HD 164595 has one known planet, , which orbits HD 164595 every 40 days. It was detected with the radial velocity technique with the SOPHIE echelle spectrograph. The planet has a minimal mass equivalent of 16 Earths.

Signal observation and SETI

In 2016, HD 164595 briefly attracted media attention after it was reported that a possible

SETI The search for extraterrestrial intelligence (SETI) is a collective term for scientific searches for intelligent extraterrestrial life, for example, monitoring electromagnetic radiation for signs of transmissions from civilizations on other pl ...

signal had been detected from the direction of the star in the previous year. The signal was only heard once and never confirmed by other telescopes, and is thought to have been due to terrestrial interference. On 15 May 2015, a brief, single radio signal at 11 GHz (2.7 cm wavelength) was observed in the direction of HD 164595 by a team led by N. N. Bursov involving

Claudio Maccone Claudio Maccone (born 6 February 1948, Torino, Italy) is an Italian SETI astronomer, space scientist and mathematician. In 2002 he was awarded the " Giordano Bruno Award" by the SETI League, "for his efforts to establish a radio observatory on ...

at the

RATAN-600 The RATAN-600 (russian: РАТАН-600 – радиоастрономический телескоп Академии наук – 600, an acronym for the " Academy of Sciences Radio Telescope – 600") is a radio telescope in Zelenchukskaya, ...

radio observatory. The signal may have been caused by terrestrial radio-frequency interference or

gravitational lens A gravitational lens is a distribution of matter (such as a cluster of galaxies) between a distant light source and an observer that is capable of bending the light from the source as the light travels toward the observer. This effect is known ...

ing from a more distant source. It was observed only once (for two seconds), by a single team, at a single telescope, giving it a

Rio Scale The Rio scale was proposed in 2000 as a means of quantifying the significance of a SETI detection. The scale was designed by Iván Almár and Jill Tarter to help policy-makers how likely, from 0 to 10, is that an extraterrestrial radio signal has ...

score of 1 (insignificant) or 2 (low). Discussions in the media from 29 August 2016 onwards featured speculation that the signal could be caused by an

isotropic beacon An isotropic beacon is a hypothetical type of transmission beacon that emits a uniform EM signal in all directions for the purposes of communication with extraterrestrial intelligence. Isotropic beacons and their relation to SETI An isotropic ...

from a Type II civilization. The senior astronomer of the

SETI Institute The SETI Institute is a not-for-profit research organization incorporated in 1984 whose mission is to explore, understand, and explain the origin and nature of life in the universe, and to use this knowledge to inspire and guide present and futu ...

Seth Shostak Seth Shostak (born July 20, 1943) is an American astronomer and author, and is currently the senior astronomer for the SETI Institute. Shostak hosts SETI's weekly radio show/podcast ''Big Picture Science'', has played himself numerous times in TV ...

, stated that confirmation by another telescope is required. Astronomer Nicholas Suntzeff of

Texas A&M University Texas A&M University (Texas A&M, A&M, or TAMU) is a public, land-grant, research university in College Station, Texas. It was founded in 1876 and became the flagship institution of the Texas A&M University System in 1948. As of late 2021, T ...

stated that the signal is in a military frequency band, and that it could have been a satellite downlink, implying that some such systems may be kept secret and therefore would be unknown to SETI scientists. SETI and METI studies followed with the Allen Telescope Array and the Boquete Optical SETI Observatory. Also, scientists at Berkeley SETI Research Center at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant u ...

observed HD 164595 using the

Green Bank Telescope The Robert C. Byrd Green Bank Telescope (GBT) in Green Bank, West Virginia, US is the world's largest fully steerable radio telescope, surpassing the Effelsberg 100-m Radio Telescope in Germany. The Green Bank site was part of the National Radi ...

as part of the

Breakthrough Listen Breakthrough Listen is a project to search for intelligent extraterrestrial communications in the Universe. With $100 million in funding and thousands of hours of dedicated telescope time on state-of-the-art facilities, it is the most comprehensi ...

program. No signal was detected at the position and frequency of the transient reported by the RATAN group. The

Special Astrophysical Observatory The Special Astrophysical Observatory of the Russian Academy of Science (SAO RAS; russian: Специальная Астрофизическая Обсерватория) is an astronomical observatory, set up in 1966 in the USSR, and now operat ...

of the

Russian Academy of Sciences The Russian Academy of Sciences (RAS; russian: Росси́йская акаде́мия нау́к (РАН) ''Rossíyskaya akadémiya naúk'') consists of the national academy of Russia; a network of scientific research institutes from across ...

has since released an official statement that the signal is of a "most probable terrestrial origin".

Footnotes

References

{{DEFAULTSORT:HD 164595 Hercules (constellation) 164595 G-type main-sequence stars 088194 BD+29 3165 J18003890+2934188 Search for extraterrestrial intelligence Planetary systems with one confirmed planet 2016 in science

Planetary system

Signal observation and SETI

See also

Footnotes

References