| Observation data Epoch J2000 Equinox J2000 (ICRS) | |
|---|---|
| Constellation | Leo[1] |
| Right ascension | 11h 46m 23.535s[2] |
| Declination | +14° 07′ 26.35″[2] |
| Apparent magnitude (V) | 8.69[3] |
| Characteristics | |
| Evolutionary stage | red giant branch[2] |
| Spectral type | K0[4] III[3] |
| U−Bcolor index | 0.69[4] |
| B−Vcolor index | 1.02[3] |
| Astrometry | |
| Radial velocity (Rv) | −11.99±0.03[3] km/s |
| Proper motion (μ) | RA: −7.371[2]mas/yr Dec.: 7.639[2]mas/yr |
| Parallax (π) | 2.8571±0.1135 mas[2] |
| Distance | 1,140 ± 50 ly (350 ± 10 pc) |
| Absolute magnitude (MV) | 0.74[3] |
| Details[3] | |
| 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 | |
| BD+14 2434,HD 102272,HIP 57428,SAO 99784[5] | |
| Database references | |
| SIMBAD | data |
HD 102272 is astar in theequatorialconstellation ofLeo. With anapparent visual magnitude of 8.69,[3] 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 onparallax measurements, but is drifting closer to the Sun with aradial velocity of −12 km/s.[3] As of 2008[update], twoextrasolar planets are known to orbit the star.[6]
This is anevolvedgiant star[3] with astellar classification of K0.[4] 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 aprojected rotational velocity of 2 km/s. It is radiating 25 times the luminosity of the Sun from its swollenphotosphere at aneffective temperature of 4,750 K.[3]
In June 2008, the discovery of twoextrasolar planets orbiting the star was announced.[6] The planets were detected using theradial velocity method with theHobby-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.[4] The pair are close to a 4:1orbital resonance with the outer planet in a high eccentricity orbit.[7]
| 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 | — | — |
