HD 164922

Last updated
HD 164922
Hercules HD 164922.png
Position of star HD 164922 in the constellation Hercules
Observation data
Epoch J2000.0       Equinox J2000.0
Constellation Hercules [1]
Right ascension 18h 02m 30.86234s [2]
Declination +26° 18 46.8050 [2]
Apparent magnitude  (V)+6.99 [3]
Characteristics
Spectral type G9V [4]
B−V color index 0.799±0.005 [3]
Astrometry
Radial velocity (Rv)20.16±0.12 [2] km/s
Proper motion (μ)RA: 389.772 mas/yr [2]
Dec.: -602.431 mas/yr [2]
Parallax (π)45.4954±0.0167  mas [2]
Distance 71.69 ± 0.03  ly
(21.980 ± 0.008  pc)
Absolute magnitude  (MV)5.29 [1]
Details
Mass 0.874 ± 0.012 [4]   M
Radius 0.999 ± 0.017 [4]   R
Luminosity 0.703 ± 0.017 [4]   L
Surface gravity (log g)4.387 ± 0.014 [4]   cgs
Temperature 5390±30 [3]   K
Metallicity [Fe/H]0.16 ± 0.05 [4]   dex
Rotation 42.3+1.3
−0.7
  d
[3]
Rotational velocity (v sin i)<2.0 [3]  km/s
Age 13.4, [5] 9.58+1.99
−1.55
[3]   Gyr
Other designations
BD +26°3151, GJ 700.2, LFT 1388, SAO 85678, HIP 88348, 2MASS J18023085+2618471
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. It is reaching the end of its main sequence life and will soon evolve to become a red giant. [2]

Contents

Nomenclature

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. [6] 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. [4] [7]

Stellar characteristics

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, [3] with estimates ranging as high as 13.4 billion years. [5] In comparison, the Sun is about 4.6 billion years old [8] and has a temperature of 5778 K. [9]

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. [4]

Planetary system

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. [10]

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. [4]

A third exoplanet, a hot super-Earth, was discovered in 2020, [3] and a fourth, Neptune-mass, in 2021. [7]

The HD 164922 planetary system [7] [11]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
d ≥4.74±0.67  M🜨 0.1023±0.001212.4584+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±0.0120.086+0.083
−0.060
c ≥14.3±1.1  M🜨 0.3411±0.003975.817+0.037
−0.038
0.096+0.088
−0.066
b ≥0.344±0.013  MJ 2.149±0.0251,198.5+3.2
−3.1
0.065+0.027
−0.029

See also

References

  1. 1 2 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv: 1108.4971 . Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015.
  2. 1 2 3 4 5 6 7 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940 . S2CID   244398875. Gaia DR3 record for this source at VizieR.
  3. 1 2 3 4 5 6 7 8 Benatti, S.; Damasso, M.; Desidera, S.; Marzari, F.; Biazzo, K.; Claudi, R.; Di Mauro, M. P.; Lanza, A. F.; Pinamonti, M.; Barbato, D.; Malavolta, L.; Poretti, E.; Sozzetti, A.; Affer, L.; Bignamini, A.; Bonomo, A. S.; Borsa, F.; Brogi, M.; Bruno, G.; Carleo, I.; Cosentino, R.; Covino, E.; Frustagli, G.; Giacobbe, P.; Gonzalez, M.; Gratton, R.; Harutyunyan, A.; Knapic, C.; Leto, G.; et al. (2020). "The GAPS Programme at TNG -- XXIII. HD 164922 d: a close-in super-Earth discovered with HARPS-N in a system with a long-period Saturn mass companion". Astronomy & Astrophysics. 639: A50. arXiv: 2005.03368 . Bibcode:2020A&A...639A..50B. doi:10.1051/0004-6361/202037939. S2CID   218538033.
  4. 1 2 3 4 5 6 7 8 9 Fulton, Benjamin J.; Howard, Andrew W.; Weiss, Lauren M.; Sinukoff, Evan; Petigura, Erik A.; Isaacson, Howard; Hirsch, Lea; Marcy, Geoffrey W.; Henry, Gregory W.; Grunblatt, Samuel K.; Huber, Daniel; Kaspar von Braun; Boyajian, Tabetha S.; Kane, Stephen R.; Wittrock, Justin; Horch, Elliott P.; Ciardi, David R.; Howell, Steve B.; Wright, Jason T.; Ford, Eric B. (2016). "Three Temperate Neptunes Orbiting Nearby Stars". The Astrophysical Journal. 830 (1): 46. arXiv: 1607.00007 . Bibcode:2016ApJ...830...46F. doi: 10.3847/0004-637X/830/1/46 . S2CID   36666883.
  5. 1 2 Takeda, Genya; et al. (February 2007). "Structure and Evolution of Nearby Stars with Planets. II. Physical Properties of ~1000 Cool Stars from the SPOCS Catalog". The Astrophysical Journal Supplement Series. 168 (2): 297–318. arXiv: astro-ph/0607235 . Bibcode:2007ApJS..168..297T. doi:10.1086/509763. S2CID   18775378 . Retrieved 2011-08-26.
  6. Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv: 1012.0707 [astro-ph.SR].
  7. 1 2 3 Rosenthal, Lee J.; Fulton, Benjamin J.; Hirsch, Lea A.; Isaacson, Howard T.; Howard, Andrew W.; Dedrick, Cayla M.; Sherstyuk, Ilya A.; Blunt, Sarah C.; Petigura, Erik A.; Knutson, Heather A.; Behmard, Aida; Chontos, Ashley; Crepp, Justin R.; Crossfield, Ian J. M.; Dalba, Paul A.; Fischer, Debra A.; Henry, Gregory W.; Kane, Stephen R.; Kosiarek, Molly; Marcy, Geoffrey W.; Rubenzahl, Ryan A.; Weiss, Lauren M.; Wright, Jason T. (2021), "The California Legacy Survey. I. A Catalog of 178 Planets from Precision Radial Velocity Monitoring of 719 Nearby Stars over Three Decades", The Astrophysical Journal Supplement Series, 255 (1): 8, arXiv: 2105.11583 , Bibcode:2021ApJS..255....8R, doi: 10.3847/1538-4365/abe23c , S2CID   235186973
  8. Fraser Cain (16 September 2008). "How Old is the Sun?". Universe Today . Retrieved 19 February 2011.
  9. Fraser Cain (15 September 2008). "Temperature of the Sun". Universe Today. Retrieved 19 February 2011.
  10. Butler, R. P.; et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal. 646 (1): 505–522. arXiv: astro-ph/0607493 . Bibcode:2006ApJ...646..505B. doi:10.1086/504701. S2CID   119067572.
  11. "HD 164922". NASA Exoplanet Archive . Retrieved 1 March 2023.