| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Libra |
| Right ascension | 15h03m 35.80651s[1] |
| Declination | −27° 50′ 27.5520″[1] |
| Apparent magnitude (V) | 8.40 + 8.42[2] |
| Characteristics | |
| Spectral type | G2 + G2[2] |
| B−V color index | 0.622[3] |
| Astrometry | |
| Radial velocity (Rv) | -16.30 km/s |
| Proper motion (μ) | RA: 156.88 mas/yr Dec.: -136.07 mas/yr |
| Parallax (π) | 19.4 ± 0.12 mas[4][5][6] |
| Distance | 168 ± 1 ly (51.5 ± 0.3 pc) |
| Orbit[2] | |
| Period (P) | ~4240 yr |
| Details[2] | |
| HD 133131 A | |
| Mass | 0.95 M☉ |
| Surface gravity (log g) | 4.39 ± 0.050 cgs |
| Temperature | 5799 ± 19 K |
| Metallicity [Fe/H] | −0.306 ± 0.016 dex |
| Age | 6.3[3] Gyr |
| HD 133131 B | |
| Mass | 0.93 M☉ |
| Surface gravity (log g) | 4.41 ± 0.045 cgs |
| Temperature | 5805 ± 15 K |
| Metallicity [Fe/H] | −0.281 ± 0.013 dex |
| Age | 5.9[3] Gyr |
| Other designations | |
CPD−27° 5116, Gaia DR1 6224633979686194688, HD 133131, HIP 73674[4] | |
| HD 133131 A: CD−27 10194A, Gaia DR2 6224633983987510528, SAO 183128, TYC 6756-1541-1, 2MASS J15033543-2750330[5] | |
| HD 133131 B: CD−27 10194B, Gaia DR2 6224633983987511552, SAO 183129, TYC 6756-867-1, 2MASS J15033579-2750273[6] | |
| Database references | |
| SIMBAD | HD 133131 |
| HD 133131 A | |
| HD 133131 B | |
HD 133131 is a binary star in the constellationofLibra. It is roughly 168 light-years (51.5 parsecs) away from the Sun.[2] It consists of two G-type main-sequence stars;[2] neither are bright enough to be seen with the naked eye.
Both components, HD 133131 A and B, are very similar to the Sun but are far older, about 6 billion years old. They also have low metallicities (50% of solar abundance), and HD 133131 A is additionally depleted in heavy elements compared to HD 133131 B, indicating a possibly past planetary engulfment event for HD 133131 B.[7]
In 2016 two planets orbiting HD 133131 A and one planet orbiting HD 133131 B were discovered utilizing the radial velocity method.[2]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥1.43 MJ | 1.44 | 649 | 0.32 | — | — |
| c | ≥0.63 MJ | 4.79 | 3925 | 0.20 | — | — |
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥2.50 MJ | 6.40 | 6119 | 0.62 | — | — |
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