Gliese 1214
 Gliese 1214 is a M-class dwarf star | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus[1] |
| Right ascension | 17h 15m 18.9337s[2] |
| Declination | +04° 57′ 50.0646″[2] |
| Apparent magnitude (V) | 14.71±0.03[3] |
| Characteristics | |
| Spectral type | M4.5[4] |
| Apparent magnitude (B) | 16.40[5] |
| Apparent magnitude (R) | 14.394 ± 0.17[5] |
| Apparent magnitude (I) | 11.52 ± 0.03[3] |
| Apparent magnitude (J) | 9.750±0.024[6] |
| Apparent magnitude (H) | 9.094±0.024[6] |
| Apparent magnitude (K) | 8.782±0.020[6] |
| B−V color index | 1.73[7] |
| V−R color index | 0.9 |
| R−I color index | 2.7 |
| Variable type | planetary transit[8] |
| Astrometry | |
| Radial velocity (Rv) | +21.1±1.0[3] km/s |
| Proper motion (μ) | RA: 580.447±0.479[2]> mas/yr Dec.: −749.588±0.221[2] mas/yr |
| Parallax (π) | 68.2653 ± 0.1723[2] mas |
| Distance | 47.8 ± 0.1 ly (14.65 ± 0.04 pc) |
| Absolute magnitude (MV) | 14.10 |
| Details | |
| Mass | 0.157±0.019[8] M☉ |
| Radius | 0.2064+0.0086 −0.0096[3] R☉ |
| Luminosity | 0.00328[8] L☉ |
| Surface gravity (log g) | 4.991±0.029[8] cgs |
| Temperature | 3026±130[8] K |
| Metallicity | 0.39±0.15[4] |
| Rotation | 125±5 d[9] |
| Age | 5–10[10] Gyr |
| Other designations | |
LHS 3275, G 139-21, NLTT 44431, 2MASS J17151894+0457496, LSPM J1715+0457, UBV M 53793, USNO-B1.0 0949-00280047, GEN# +9.80139021.[5] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| ARICNS | data |
| Extrasolar Planets Encyclopaedia | data |
Gliese 1214 is a dim M4.5[4] red dwarf in the constellation Ophiuchus with an apparent magnitude of 14.7.[3] It is located at a distance of approximately 47 light years from Earth.[11] The star is about one-fifth the radius of the Sun[12] with a surface temperature estimated to be 3000 K (2730 °C; 4940 °F).[12] Its luminosity is only 0.33% that of the Sun.[12]
The estimate for the stellar radius is 15% larger than predicted by theoretical models.[8] It also shows a 1% intrinsic variability in the near-infrared probably caused by stellar spots.[3] The star is rotating slowly, with a period that is most likely an integer multiple of 53 days. It is probably at least three billion years old and a member of the old thin disk of the Milky Way.[3] Although GJ 1214 has a low to moderate level of magnetic activity, it does undergo flares and is a source of X-ray emission with a base luminosity of 7.4×1025 erg s−1. The temperature of the stellar corona is estimated to be about 3.5×106 K.[10]
Planetary system[]
In mid-December 2009, a team of Harvard-Smithsonian astronomers announced the discovery of a companion extrasolar planet, Gliese 1214 b, potentially composed largely of water and having the mass and diameter of a super-Earth.[8][12]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 8.17±0.43[13] M
|