Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Hercules |
Right ascension | 18h 02m 30.86234s [1] |
Declination | +26° 18′ 46.8050″ [1] |
Apparent magnitude (V) | +6.99 [2] |
Characteristics | |
Spectral type | G9V [3] |
B−V color index | 0.799±0.005 [2] |
Astrometry | |
Radial velocity (Rv) | 20.16±0.12 [1] km/s |
Proper motion (μ) | RA: 389.772 mas/yr [1] Dec.: -602.431 mas/yr [1] |
Parallax (π) | 45.4954 ± 0.0167 mas [1] |
Distance | 71.69 ± 0.03 ly (21.980 ± 0.008 pc) |
Details | |
Mass | 0.874 ± 0.012 [3] M☉ |
Radius | 0.999 ± 0.017 [3] R☉ |
Luminosity | 0.703 ± 0.017 [3] L☉ |
Surface gravity (log g) | 4.387 ± 0.014 [3] cgs |
Temperature | 5390±30 [2] K |
Metallicity [Fe/H] | 0.16 ± 0.05 [3] dex |
Rotation | 42.3+1.3 −0.7 d [2] |
Rotational velocity (v sin i) | <2.0 [2] km/s |
Age | 13.4, [4] 9.58+1.99 −1.55 [2] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
HD 164922 is a seventh magnitude G-type main sequence star in the constellation of Hercules. To view it, binoculars or a telescope are necessary, as it is too faint to be visible to the naked eye. It is 71.7 light-years (22.0 parsecs ) distant from the Earth. [1] It will soon evolve away from the main-sequence and expand to become a red giant.[ citation needed ]
The name HD 164922 derives directly from the fact that the star is the 164,922nd star listed in the Henry Draper catalog. The designation b for its planet derives from the order of discovery. The designation of b is given to the first planet found orbiting a given star, followed by the other lowercase letters of the alphabet. [5] In the case of HD 164922, only one was discovered, which was designated b, followed by three more planets, which were designated c, d, and e. [3] [6]
HD 164922 is a G-type main sequence star that is approximately 87% the mass of and 99% the radius of the Sun. It has a temperature of 5390 K and is about 10 billion years old, [2] with estimates ranging as high as 13.4 billion years. [4] In comparison, the Sun is about 4.6 billion years old [7] and has a temperature of 5778 K. [8]
The star is metal-rich, with a metallicity ([Fe/H]) of 0.16, or 144% the solar amount. This is particularly odd for a star as old as HD 164922. Its luminosity (L☉) is 70% of the solar luminosity. [3]
On 15 July 2006, a long period Saturn-mass exoplanet was announced orbiting around HD 164922. This planet orbits at 2.11 AU from the star with a low eccentricity value of 0.05. [9]
Almost exactly ten years later in 2016, another exoplanet, though less massive than the first planet, was discovered orbiting farther in from the star. This planet has a minimum mass of nearly 13 times that of Earth, meaning it is possibly a Neptune-like planet. [3]
A third exoplanet, a hot super-Earth, was discovered in 2020, [2] and a fourth, Neptune-mass, in 2021. [6]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
d | ≥4.74±0.67 M🜨 | 0.1023±0.0012 | 12.4584+0.0019 −0.0023 | 0.18+0.17 −0.12 | — | — |
e | ≥10.52+0.99 −0.97 M🜨 | 0.2292+0.0026 −0.0027 | 41.763±0.012 | 0.086+0.083 −0.060 | — | — |
c | ≥14.3±1.1 M🜨 | 0.3411±0.0039 | 75.817+0.037 −0.038 | 0.096+0.088 −0.066 | — | — |
b | ≥0.344±0.013 MJ | 2.149±0.025 | 1,198.5+3.2 −3.1 | 0.065+0.027 −0.029 | — | — |
14 Herculis or 14 Her is the Flamsteed designation of a K-type main-sequence star 58.4 light-years away in the constellation Hercules. It is also known as HD 145675. Because of its apparent magnitude, the star cannot be seen with the naked eye. As of 2021, 14 Herculis is known to host two exoplanets in orbit around the star.
Rho Coronae Borealis is a yellow dwarf star 57.1 light-years away in the constellation of Corona Borealis. The star is thought to be similar to the Sun with nearly the same mass, radius, and luminosity. It is orbited by four known exoplanets.
HD 164922 b is an exoplanet orbiting the star HD 164922 about 72 light-years from Earth in the constellation Hercules. Its inclination is not known, and its true mass may be significantly greater than the radial velocity lower limit of 0.36 Jupiter masses. The planet also has a low eccentricity, unlike most other long period extrasolar planets – 0.05 – about the same as Jupiter and Saturn in the Solar System. The exoplanet was found by using the radial velocity method, from radial-velocity measurements via observation of Doppler shifts in the spectrum of the planet's parent star.
HD 66428 is a G-type main sequence star located approximately 174 light-years away in the constellation of Monoceros. This star is similar to the Sun with an apparent magnitude of 8.25, an effective temperature of 5705 ± 27 K and a solar luminosity 1.28. Its absolute magnitude is 11.1 while its U-V color index is 0.71. It is considered an inactive star and it is metal-rich . This star has a precise mass of 1.14552 solar masses. This precision comes from the Corot mission that measured asteroseismology.
HD 154345 is a star in the northern constellation of Hercules. With an apparent visual magnitude of +6.76 it is a challenge to view with the naked eye, but using binoculars it is an easy target. The distance to this star is 59.6 light years based on parallax, but it is drifting closer with a radial velocity of −47 km/s. At least one exoplanet is orbiting this star.
HD 107148 is an 8th magnitude primary of the binary star system located approximately 161 light years away in the constellation of Virgo. It is a yellow dwarf with a luminosity 1.41 times the Sun. It is twice as enriched with heavy elements than the Sun. The HD 107148 exhibits a magnetic activity cycle with a period around 6 years.
HD 68988 is a star in the northern constellation of Ursa Major. It has been given the proper name Násti, which means star in the Northern Sami language. The name was selected in the NameExoWorlds campaign by Norway, during the 100th anniversary of the IAU. HD 68988 is too faint to be seen with the naked eye, having an apparent visual magnitude of 8.20. The star is located at a distance of 199 light years from the Sun based on parallax. It is drifting closer with a radial velocity of −69 km/s and is predicted to come as close as 78 light-years in 617,000 years.
HD 114762 b is a small red dwarf star, in the HD 114762 system, formerly thought to be a massive gaseous extrasolar planet, approximately 126 light-years (38.6 pc) away in the constellation of Coma Berenices. This optically undetected companion to the late F-type main-sequence star HD 114762 was discovered in 1989 by Latham, et al., and confirmed in an October 1991 paper by Cochran, et al. It was thought to be the first discovered exoplanet
HD 85512 is a solitary K-type main-sequence star 36.8 light-years away in the constellation Vela. It is about 1 billion years older than the Sun. It is extremely chromospherically inactive, only slightly more active than Tau Ceti. It exhibits a long-term variability and was thought to host one low-mass planet, although this is now doubtful.
HD 24040 is a metal-rich G-type star located approximately 152 light-years away in the constellation of Taurus. In 2006 a long-period planet was discovered.
HD 10180, also designated 2MASS J01375356-6030414, is a Sun-like star in the southern constellation Hydrus that is notable for its large planetary system. Since its discovery, at least six exoplanets have been observed orbiting it, and some studies have proposed up to nine potential planets, which would make it potentially the largest of all known planetary systems, including the Solar System.
HD 106515 is a binary star in the constellation of Virgo.
Gliese 251, also known as HIP 33226 or HD 265866, is a star located about 18 light years away from the Solar System. Located in the constellation of Gemini, it is the nearest star in this constellation. It is located near the boundary with Auriga, 49 arcminutes away from the bright star Theta Geminorum; due to its apparent magnitude of +9.89 it cannot be observed with the naked eye. The closest star to Gliese 251 is QY Aurigae, which is located 3.5 light years away.
HD 164922 c is an exoplanet orbiting the star HD 164922 about 72 light-years from Earth in the constellation Hercules. The exoplanet was found by using the radial velocity method, from radial-velocity measurements via observation of Doppler shifts in the spectrum of the planet's parent star.
V1298 Tauri is a young weakly-lined T Tauri star that is part of the Taurus-Auriga association in the Taurus Molecular Cloud. Alternatively it is part of a proposed moving group, called Group 29 that is slightly older. The system has four transiting exoplanets, discovered with the Kepler space telescope in the K2 mission. One of the planets was discovered in August 2019 and the other three were discovered in November 2019 by the same team.
HD 189567 is a G3V star located 58.5 light years away, in the constellation of Pavo. The star HD 189567 is also known as Gliese 776, CD-67 2385, and HR 7644.
HD 42618 is a well-studied star with an exoplanetary companion in the equatorial constellation of Orion. With an apparent visual magnitude of 6.85 it is too faint to be readily visible to the naked eye. This system is located at a distance of 79.6 light years from the Sun based on parallax measurements. It has a relatively high proper motion, traversing the celestial sphere at an angular rate of 0.321″ per year. HD 42618 is drifting closer with a radial velocity of −53.5 km/s and is predicted to come as near as 42.6 light-years in around 297,000 years.