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 Post-detection policy#Significance of transmission, Rio Scale 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 from a Kardashev scale#Definition, Type II civilization. The senior astronomer of the SETI Institute, Seth Shostak, stated that confirmation by another telescope is required. Astronomer Nicholas Suntzeff of Texas A&M University 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 (Messaging Extraterrestrial Intelligence), 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 observed HD 164595 using the Green Bank Telescope as part of the Breakthrough Listen program. No signal was detected at the position and frequency of the transient reported by the RATAN group. The Special Astrophysical Observatory of the Russian Academy of Sciences has since released an official statement that the signal is of a "most probable terrestrial origin".

Footnotes

References

{{DEFAULTSORT:HD 164595 Hercules (constellation) Henry Draper Catalogue objects, 164595 G-type main-sequence stars Hipparcos objects, 088194 Durchmusterung objects, BD+29 3165 2MASS objects, 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