HD 133131
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Libra |
| A | |
| Right ascension | 15h 03m 35.44599s |
| Declination | −27° 50′ 33.2195″ |
| Apparent magnitude (V) | 8.40 |
| B | |
| Right ascension | 15h 03m 35.80805s |
| Declination | −27° 50′ 27.5843″ |
| Apparent magnitude (V) | 8.42 |
| Characteristics | |
| A | |
| Evolutionary stage | main sequence |
| Spectral type | G2V |
| B−V color index | +0.622 |
| B | |
| Evolutionary stage | main sequence |
| Spectral type | G2V |
| B−V color index | +0.622 |
| Astrometry | |
| A | |
| Radial velocity (Rv) | −16.37±0.19 km/s |
| Proper motion (μ) | RA: +156.227 mas/yr Dec.: −133.767 mas/yr |
| Parallax (π) | 19.4325±0.0265 mas |
| Distance | 167.8 ± 0.2 ly (51.46 ± 0.07 pc) |
| B | |
| Radial velocity (Rv) | −15.70±0.18 km/s |
| Proper motion (μ) | RA: +159.010 mas/yr Dec.: −139.133 mas/yr |
| Parallax (π) | 19.4131 ± 0.0293 mas |
| Distance | 168.0 ± 0.3 ly (51.51 ± 0.08 pc) |
| Orbit | |
| Period (P) | ~4240 yr |
| Details | |
| HD 133131A | |
| Mass | 0.95 M☉ |
| Radius | 1.00 R☉ |
| Luminosity | 9.6 L☉ |
| Surface gravity (log g) | 4.39±0.050 cgs |
| Temperature | 5,799±19 K |
| Metallicity [Fe/H] | −0.306±0.016 dex |
| Rotation | 23 days |
| Rotational velocity (v sin i) | 4.0 km/s |
| Age | 6.3 Gyr |
| HD 133131B | |
| Mass | 0.93 M☉ |
| Radius | 1.01 R☉ |
| Luminosity | 0.98 L☉ |
| Surface gravity (log g) | 4.41±0.045 cgs |
| Temperature | 5,805±15 K |
| Metallicity [Fe/H] | −0.281±0.013 dex |
| Rotation | 22 days |
| Rotational velocity (v sin i) | 7.0 km/s |
| Age | 5.9 Gyr |
| Other designations | |
| CPD−27°5116, HD 133131, HIP 73674 | |
| HD 133131A: SAO 183128, TYC 6756-1541-1, 2MASS J15033543-2750330 | |
| HD 133131B: SAO 183129, TYC 6756-867-1, 2MASS J15033579-2750273 | |
| Database references | |
| SIMBAD | The system |
| A | |
| B | |
| Exoplanet Archive | data |
HD 133131 is a binary star in the constellation of Libra. It is 168 light-years (51.5 parsecs) away from the Sun. It consists of two G-type main-sequence stars; neither are bright enough to be seen with the naked eye. The star was first catalogued as a binary in 1972.
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 133131A is additionally depleted in heavy elements compared to HD 133131B, indicating a possibly past planetary engulfment event for HD 133131 B.