HD 72659

HD 72659

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Hydra
Right ascension	08^h 34^m 03.18984^s[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)	−18.29±0.12[1] km/s
Proper motion (μ)	RA: −112.313±0.026 mas/yr[1] Dec.: −96.386±0.018 mas/yr[1]
Parallax (π)	19.2582 ± 0.0271 mas[1]
Distance	169.4 ± 0.2 ly (51.93 ± 0.07 pc)
Absolute magnitude (MV)	3.98[2]
Details[4]
Mass	1.07±0.02 M☉
Radius	1.38±0.02 R☉
Luminosity	2.16±0.01 L☉
Surface gravity (log g)	4.19±0.02 cgs
Temperature	5,956±43 K
Metallicity [Fe/H]	−0.04±0.01[2] dex
Rotational velocity (v sin i)	5.1[5] km/s
Age	7.0±0.7 Gyr
Other designations
BD−01°2075, Gaia DR2 3073443760538892032, HD 72659, HIP 42030, SAO 136045, 2MASS J08340320-0134056[6]
Database references
SIMBAD	data

HD 72659 is a star in the equatorial constellation of Hydra. With an apparent visual magnitude of 7.46,^[2] his 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 −18.3 km/s.^[1]

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,^[4] and is spinning with a projected rotational velocity of 5.1 km/s.^[5] 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.^[4] 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.^[7] This is a superjovian planet with an eccentric orbit, completing a lap around its host star every 9.9 years.^[8] 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.^[9]

The HD 72659 planetary system^[9]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (years)	Eccentricity	Inclination	Radius
b	2.988+2.586 −0.098 MJ	4.691+0.185 −0.202	9.718+0.052 −0.043	0.257+0.014 −0.016	77.583+39.898 −39.755°	—
c	18.806+4.442 −4.796 MJ	13.959+0.884 −0.861	49.850+3.805 −3.287	0.091+0.055 −0.048	14.279+4.366 −2.678°	—

See also

• HD 73256
• List of extrasolar planets

References

1. 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.
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. S2CID 119257644.
3. 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. Bonfanti, A.; et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics. 575. A18. arXiv:1411.4302. Bibcode:2015A&A...575A..18B. doi:10.1051/0004-6361/201424951. S2CID 54555839.
5. Luck, R. Earle (January 2017). "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants". The Astronomical Journal. 153 (1): 19. arXiv:1611.02897. Bibcode:2017AJ....153...21L. doi:10.3847/1538-3881/153/1/21. S2CID 119511744. 21.
6. "HD 72659". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-01-24.
7. Butler, R. Paul; et al. (2003). "Seven New Keck Planets Orbiting G and K Dwarfs". The Astrophysical Journal. 582 (1): 455–466. Bibcode:2003ApJ...582..455B. CiteSeerX 10.1.1.7.6988. doi:10.1086/344570. S2CID 17608922.
8. 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. hdl:2299/1103. S2CID 119067572. Archived from the original on 2019-12-07. Retrieved 2009-12-23.
9. Feng, Fabo; Butler, R. Paul; et al. (August 2022). "3D Selection of 167 Substellar Companions to Nearby Stars". The Astrophysical Journal Supplement Series. 262 (21): 21. arXiv:2208.12720. Bibcode:2022ApJS..262...21F. doi:10.3847/1538-4365/ac7e57. S2CID 251864022.

External links