HD 77338
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pyxis |
| Right ascension | 09h 01m 12.4938s[1] |
| Declination | −25° 31′ 37.4333″[1] |
| Apparent magnitude (V) | 8.59 |
| Characteristics | |
| Evolutionary stage | subgiant star |
| Spectral type | K0IV |
| Astrometry | |
| Radial velocity (Rv) | 8.209[2] km/s |
| Proper motion (μ) | RA: 40.095[2] mas/yr Dec.: -271.640[2] mas/yr |
| Parallax (π) | 21.8739 ± 0.0192 mas[2] |
| Distance | 149.1 ± 0.1 ly (45.72 ± 0.04 pc) |
| Details[3][4] | |
| Mass | 0.942 M☉ |
| Luminosity | 0.708 L☉ |
| Surface gravity (log g) | 4.42 cgs |
| Temperature | 5315 K |
| Metallicity [Fe/H] | 0.16 dex |
| Rotation | 33.4±10.0[5] |
| Rotational velocity (v sin i) | 1.3 km/s |
| Age | 9.5 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 77338 is a K-type subgiant star which has recently exhausted its hydrogen fuel and has started to expand. Its surface temperature is 5315 K.[3] HD 77338 is enriched in its concentration of heavy elements compared to the Sun, with a metallicity Fe/H index of 0.16 but is much older at an age of 9.5 billion years.[3]
HD 77338 is unusually enriched in heavy elements for a star of its age. The anomalously high abundance of ions of manganese may indicate the star has recently passed through the common shell stage (engulfed a planet).[6]
Planetary system
In 2012, one planet, named HD 77338b, was discovered by the radial velocity method on a tight orbit with uncertain eccentricity.[7] Its equilibrium temperature is 954.8 K.[8]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥15.9+4.7 −5.3 M🜨 |
0.0614+0.0031 −0.0034 |
5.73610±0.0015 | 0.09+0.22 −0.09 |
— | — |
References
- ^ a b c "HD 77338". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-01-19.
- ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
- ^ a b c Masses, Oxygen and Carbon abundances in CHEPS dwarf stars, 2018, arXiv:1811.05011
- ^ The metal rich abundance pattern – spectroscopic properties and abundances for 107 main-sequence stars, 2017, arXiv:1703.05077
- ^ Rotation periods of late-type dwarf stars from time-series high-resolution spectroscopy of chromospheric indicators, 2015, arXiv:1506.08039
- ^ Abundances in the atmosphere of the metal-rich planet-host star HD 77338, 2015, arXiv:1505.05843
- ^ a b A hot Uranus orbiting the super metal-rich star HD77338 and the Metallicity - Mass Connection, 2012, arXiv:1207.1012
- ^ HD 77338 b is an exoplanet orbiting the star HD 77338, located about 149.3 light-years (45.8 pc) away from Solar System. Its discovery was publicly announced on 2012
- ^ ACCURATE, EMPIRICAL RADII AND MASSES OF PLANETS AND THEIR HOST STARS WITH GAIA PARALLAXES, 2016, arXiv:1609.04389
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