HD 125612
Binary star system in the constellation Virgo
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HD 125612 is a binary star system with three exoplanetary companions[3][8] in the equatorial constellation of Virgo. It is too dim to be visible to the naked eye, having an apparent visual magnitude of 8.31.[3] The system is located at a distance of 188 light years from the Sun based on parallax measurements, but it is drifting closer with a radial velocity of −18 km/s.[2]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Virgo[1] |
| Right ascension | 14h 20m 53.517665s[2] |
| Declination | −17° 28′ 53.489700″[2] |
| Apparent magnitude (V) | 8.31[3] / ? |
| Characteristics | |
| Spectral type | G3V[3] + M3- 4V[4] |
| Apparent magnitude (B) | 8.938[1] |
| Apparent magnitude (J) | 7.179±0.023[1] |
| Apparent magnitude (H) | 6.950±0.059[1] |
| Apparent magnitude (K) | 6.838±0.026[1] |
| B−V color index | 0.628±0.018[1] |
| Astrometry | |
| Radial velocity (Rv) | −18.25±0.15[2] km/s |
| Proper motion (μ) | RA: −60.260±0.034 mas/yr[2] Dec.: −67.314±0.027 mas/yr[2] |
| Parallax (π) | 17.2897±0.0279 mas[2] |
| Distance | 188.6 ± 0.3 ly (57.84 ± 0.09 pc) |
| Absolute magnitude (MV) | 4.65[1] |
| Position (relative to HD 125612 A)[4] | |
| Component | HD 125612 B |
| Angular distance | 89.994±0.066″ |
| Position angle | 162.682±0.052° |
| Projected separation | ~4,750 AU |
| Details | |
| Mass | 1.091±0.027 M☉[3] 1.133±0.025[5] M☉ |
| Radius | 1.05±0.08[3] R☉ |
| Luminosity | 1.09[3] L☉ |
| Surface gravity (log g) | 4.41±0.05[3] cgs |
| Temperature | 5,900±18[3] K |
| Metallicity [Fe/H] | 0.23±0.014[3] dex |
| Rotational velocity (v sin i) | 3.2[6] km/s |
| Age | 1.351±1.127[5] Gyr |
| HD 125612 B | |
| Mass | 0.184±0.012[4] M☉ |
| Age | 1-5[4] Gyr |
| Other designations | |
| BD−16°3844, HD 125612, HIP 70123, SAO 158501, PPM 228650, GSC 06143-01696[7] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
The yellow-hued primary component, designated HD 125612 A, is an ordinary G-type main-sequence star with a stellar classification of G3V,[3] which indicates it is generating energy through hydrogen fusion at its core. It is about 1.4[5] billion years old and is rich in heavy elements, having a 70% greater abundance of iron compared to the Sun. The star has 109% of the mass and 105% of the girth of the Sun. It is radiating 109% of the luminosity of the Sun from its photosphere at an effective temperature of 5,900 K.[3]
A red dwarf companion star, HD 125612 B, was detected in 2009 at a projected separation of 4750 AU. The possibility of a much closer companion to the primary star was also suggested, though this will need more observation to better define.[4]
Planetary system
_HD_125612_Star_system.png)
There are three known exoplanets in orbit around HD 125612 A. The first was reported in 2007 and designated HD 125612 b, but it did not fully resolve the stellar velocity variations and it was clear there were other companions.[9] Two additional companions, HD 125612 c and d, were reported in 2009.[4] In 2022, the inclination and true mass of the outer planet HD 125612 d were measured via astrometry.[10]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| c | ≥0.055±0.01 MJ | 0.0524±0.0031 | 4.15514±0.00026 | 0.049±0.038 | — | — |
| b | ≥3.1±0.4 MJ | 1.372±0.083 | 557.04±0.35 | 0.4553±0.0055 | — | — |
| d | 7.178+0.932 −0.445 MJ |
3.982+0.159 −0.174 |
2822.7+15.0 −15.3 |
0.115±0.012 | 88.195+16.306 −15.980° |
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