HD 103197
HD 103197 is a star with a planetary companion in the southern constellation of Centaurus. It has an apparent visual magnitude of 9.40, which is too faint to be viewed with the naked eye. Based on parallax measurements, HD 103197 is located at a distance of 187 light years from the Sun. It is drifting closer with a radial velocity of −4.6 km/s.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 11h 52m 52.97822s |
| Declination | –50° 17′ 34.1592″ |
| Apparent magnitude (V) | 9.40 |
| Characteristics | |
| Spectral type | K1V(p) |
| Apparent magnitude (B) | 10.26 |
| Apparent magnitude (J) | 7.916±0.023 |
| Apparent magnitude (H) | 7.600±0.051 |
| Apparent magnitude (K) | 7.426±0.027 |
| B−V color index | 0.860±0.023 |
| Astrometry | |
| Radial velocity (Rv) | −4.55±0.21 km/s |
| Proper motion (μ) | RA: –80.938 mas/yr Dec.: +7.188 mas/yr |
| Parallax (π) | 17.4700 ± 0.0294 mas |
| Distance | 186.7 ± 0.3 ly (57.24 ± 0.10 pc) |
| Absolute magnitude (MV) | 5.79 |
| Details | |
| Mass | 0.90 M☉ |
| Radius | 0.95±0.02 R☉ |
| Luminosity | 0.566+0.002 −0.001 L☉ |
| Surface gravity (log g) | 4.40±0.11 cgs |
| Temperature | 5,303±58 K |
| Metallicity [Fe/H] | 0.21±0.04 dex |
| Rotation | 51±5 d |
| Rotational velocity (v sin i) | 0.602 km/s |
| Age | 4.872±4.294 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
This is a K-type main-sequence star with a stellar classification of K1V(p). In 1978, N. Houk noted that the cores of the star's H and K lines are weakly in emission; hence the 'p' code indicating a spectral peculiarity. The star is an estimated five billion years old with a projected rotational velocity of approximately 0.6 km/s and it appears to be very inactive. It has 90% of the mass and 95% of the radius of the Sun. Its metal content is five-eighths greater than in the Sun.
In 2009, a gas giant exoplanet companion was discovered using the radial velocity method. This object is orbiting the host star at a distance of 0.249 AU (37.2 Gm) and a period of 47.84 d, with what is assumed to be a circular orbit.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥31.2 ± 2.0 M🜨 | 0.249 ± 0.004 | 47.84 ± 0.03 | 0.0(fixed) | — | — |