Astronomy:HD 72659
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Hydra |
| Right ascension | 08h 34m 03.18984s[1] |
| Declination | −01° 34′ 05.5822″[1] |
| Apparent magnitude (V) | 7.46[2] |
| Characteristics | |
| Spectral type | G2V[3] |
| B−V color index | +0.612±0.015[2] |
| Astrometry | |
| Radial velocity (Rv) | −18.203+0.024 −0.029[4] km/s |
| Proper motion (μ) | RA: −112.313(26)[1] mas/yr Dec.: −96.386(18)[1] mas/yr |
| Parallax (π) | 19.2582 ± 0.0271[1] mas |
| Distance | 169.4 ± 0.2 ly (51.93 ± 0.07 pc) |
| Absolute magnitude (MV) | 3.98[2] |
| Details[4] | |
| Mass | 1.033±0.025 M☉ |
| Radius | 1.36±0.06 R☉ |
| Luminosity | 2.16±0.01[5] L☉ |
| Surface gravity (log g) | 4.19±0.02[5] cgs |
| Temperature | 5,929±61 K |
| Metallicity [Fe/H] | −0.02±0.06 dex |
| Rotational velocity (v sin i) | 1.6±0.9 km/s |
| Age | 8±1 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HD 72659 is a star in the equatorial constellation of Hydra. With an apparent visual magnitude of 7.46,[2] its yellow-hued star is too faint to be viewed with the naked eye. Parallax measurements provide a distance estimate of 169.4 light years from the Sun, and it has an absolute magnitude of 3.98.[2] The star is drifting closer with a radial velocity of −18.2 km/s.[4]
This is a Sun-like main sequence star with a stellar classification of G2V,[3] indicating that it is generating energy through core hydrogen fusion. It is older than the Sun with an age of about seven billion years,[5] and is spinning with a projected rotational velocity of 5.1 km/s.[7] The star has 7% greater mass than the Sun and a 38% larger radius. It is radiating more than double the Sun's luminosity from its photosphere at an effective temperature of 5,956 K.[5] The metallicity of the stellar atmosphere is similar to the Sun.[2]
Planetary system
An extrasolar planet was discovered orbiting this star in 2003 via the Doppler method.[8] This is a superjovian planet with an eccentric orbit, completing a lap around its host star every 9.9 years.[9] In 2022, the inclination and true mass of HD 72659 b were measured via astrometry, along with the detection of a second substellar companion, likely a brown dwarf.[10] The orbit of the brown dwarf lies in the so-called brown dwarf desert, regions with a deficit of brown dwarfs. The host star is very old and thus HD 72659 b and c can not be directly imaged, even with the most modern equipment such as the James Webb Space Telescope. The moderate eccentricity of planet b may be the result of Kozai-Lidov oscillations.[4]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (years) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 3.0+2.6 −0.1[10] MJ |
4.607±0.039 | 9.72±0.03 | 0.239±0.001 | 78±40[10]° | — |
| c | 19.4+0.8 −0.5 MJ |
21.5+0.5 −0.4 |
97.1+3.4 −2.5 |
0.114+0.002 −0.003 |
40±2° | — |
See also
- HD 73256
- List of extrasolar planets
References
- ↑ 1.0 1.1 1.2 1.3 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars". Michigan Spectral Survey 5. Bibcode: 1999MSS...C05....0H.
- ↑ 4.0 4.1 4.2 4.3 4.4 Ruggieri, A.; Sozzetti, A.; Desidera, S.; Mesa, D.; Gratton, R.; Marzari, F.; Bonavita, M.; Biazzo, K. et al. (2025). "The GAPS programme at TNG LXVIII. Characterization of the outer substellar companion around HD 72659 with a multitechnique approach". Monthly Notices of the Royal Astronomical Society 542 (2): 1233–1247. doi:10.1093/mnras/staf1251.
- ↑ 5.0 5.1 5.2 5.3 Bonfanti, A. et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics 575: A18. doi:10.1051/0004-6361/201424951. Bibcode: 2015A&A...575A..18B. http://www.aanda.org/articles/aa/full_html/2015/03/aa24951-14/aa24951-14.html.
- ↑ "HD 72659". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+72659.
- ↑ Luck, R. Earle (January 2017). "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants". The Astronomical Journal 153 (1): 19. doi:10.3847/1538-3881/153/1/21. 21. Bibcode: 2017AJ....153...21L.
- ↑ Butler, R. Paul et al. (2003). "Seven New Keck Planets Orbiting G and K Dwarfs". The Astrophysical Journal 582 (1): 455–466. doi:10.1086/344570. Bibcode: 2003ApJ...582..455B.
- ↑ Butler, R. P. et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal 646 (1): 505–522. doi:10.1086/504701. Bibcode: 2006ApJ...646..505B. http://www.iop.org/EJ/article/0004-637X/646/1/505/64046.html. Retrieved 2009-12-23.
- ↑ 10.0 10.1 10.2 Feng, Fabo et al. (August 2022). "3D Selection of 167 Substellar Companions to Nearby Stars". The Astrophysical Journal Supplement Series 262 (21): 21. doi:10.3847/1538-4365/ac7e57. Bibcode: 2022ApJS..262...21F.
External links
Coordinates: 
08h 34m 03.1895s, −01° 34′ 05.583″
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