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]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| 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) | −18.29±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 | |
| Database references | |
| SIMBAD | data |
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]
| 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° | — |