HD 102272 is a star in the equatorial constellation of Leo. With an apparent visual magnitude of 8.69,[2] it is too faint to be visible to the naked eye. The star is located at a distance of approximately 1,140 light years based on parallax measurements, but is drifting closer to the Sun with a radial velocity of −12 km/s.[2] As of 2008[update], two extrasolar planets are known to orbit the star.[5]
| Observation data Epoch J2000.0 (ICRS) Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Leo |
| Right ascension | 11h 46m 23.535s[1] |
| Declination | +14° 07′ 26.35″[1] |
| Apparent magnitude (V) | 8.69[2] |
| Characteristics | |
| Spectral type | K0[3] III[2] |
| U−B color index | 0.69[3] |
| B−V color index | 1.02[2] |
| Astrometry | |
| Radial velocity (Rv) | −11.99±0.03[2] km/s |
| Proper motion (μ) | RA: −7.371[1] mas/yr Dec.: 7.639[1] mas/yr |
| Parallax (π) | 2.8571 ± 0.1135 mas[1] |
| Distance | 1,140 ± 50 ly (350 ± 10 pc) |
| Absolute magnitude (MV) | 0.74[2] |
| Details[2] | |
| Mass | 1.01±0.122 M☉ |
| Radius | 8.02±2.14 R☉ |
| Luminosity | 25 L☉ |
| Surface gravity (log g) | 2.57±0.04 cgs |
| Temperature | 4,750±10 K |
| Metallicity [Fe/H] | −0.49±0.06 dex |
| Rotational velocity (v sin i) | 2.10±0.90 km/s |
| Age | 8.13 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an evolved giant star[2] with a stellar classification of K0.[3] It is an estimated eight billion years old and has expanded to eight times the Sun's radius. The star has about the same mass as the Sun and is spinning with a projected rotational velocity of 2 km/s. It is radiating 25 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,750 K.[2]
Planetary system
In June 2008, the discovery of two extrasolar planets orbiting the star was announced.[5] The planets were detected using the radial velocity method with the Hobby-Eberly Telescope. The radial velocity data clearly shows the presence of the inner planet (HD 102272 b). Although there is evidence for another planet, there is insufficient data to unambiguously determine its orbit.[3] The pair are close to a 4:1 orbital resonance with the outer planet in a high eccentricity orbit.[6]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | >5.9 ± 0.2 MJ | 0.614 ± 0.001 | 127.58 ± 0.30 | 0.05 ± 0.04 | — | — |
| c | >2.6 ± 0.4 MJ | 1.57 ± 0.05 | 520 ± 26 | 0.68 ± 0.06 | — | — |
See also
References
External links
- "Notes for star HD 102272". Extrasolar Planets Encyclopaedia. Archived from the original on July 25, 2008. Retrieved 2008-07-01.
- "HD 102272". Exoplanets. Archived from the original on 2009-11-24. Retrieved 2008-11-09.