Kepler-444
Kepler-444 (or KOI-3158, KIC 6278762, 2MASS J19190052+4138043, BD+41°3306) is a triple star system, estimated to be 11.2 billion years old (more than 80% of the age of the universe), approximately 119 light-years (36 pc) away from Earth in the constellation Lyra. On 27 January 2015, the Kepler spacecraft is reported to have confirmed the detection of five sub-Earth-sized rocky exoplanets orbiting the main star. The star is a K-type main sequence star. All of the planets are far too close to their star to harbour life forms.
Adaptive optics image of the Kepler-444 system from Zhang et al. | |
| Observation data Epoch J2000 Equinox 2000 | |
|---|---|
| Constellation | Lyra |
| Kepler-444 A | |
| Right ascension | 19h 19m 00.5489s |
| Declination | +41° 38′ 04.582″ |
| Apparent magnitude (V) | 8.86 |
| Kepler-444 B/C | |
| Right ascension | 19h 19m 00.3922s |
| Declination | +41° 38′ 04.013″ |
| Characteristics | |
| Spectral type | K0V |
| Astrometry | |
| Kepler-444 A | |
| Radial velocity (Rv) | −123.05±0.17 km/s |
| Proper motion (μ) | RA: 94.639(13) mas/yr Dec.: −632.269(14) mas/yr |
| Parallax (π) | 27.3578 ± 0.0125 mas |
| Distance | 119.22 ± 0.05 ly (36.55 ± 0.02 pc) |
| Kepler-444 B/C | |
| Proper motion (μ) | RA: 94.508(55) mas/yr Dec.: −630.781(78) mas/yr |
| Parallax (π) | 27.6079 ± 0.0545 mas |
| Distance | 118.1 ± 0.2 ly (36.22 ± 0.07 pc) |
| Orbit | |
| Primary | A |
| Companion | BC |
| Period (P) | 324+31 −25 yr |
| Semi-major axis (a) | 52.2+3.3 −2.7 AU |
| Eccentricity (e) | 0.55+0.05 −0.05 |
| Inclination (i) | 85.4+0.3 −0.4° |
| Longitude of the node (Ω) | 250.7+0.2 −0.2° |
| Periastron epoch (T) | JD 2537060+10881 −8533 |
| Argument of periastron (ω) (secondary) | 227.3+6.5 −5.2° |
| Details | |
| A | |
| Mass | 0.754±0.030 M☉ |
| Radius | 0.753±0.010 R☉ |
| Surface gravity (log g) | 4.595±0.060 cgs |
| Temperature | 5046±74.0 K |
| Metallicity [Fe/H] | −0.55±0.07 dex |
| Rotation | 49.40±6.04 d |
| Age | 11.00±0.8 Gyr |
| B | |
| Mass | 0.307+0.009 −0.008 M☉ |
| Surface gravity (log g) | 5.0±0.2 cgs |
| Temperature | 3,464±200 K |
| C | |
| Mass | 0.296±0.008 M☉ |
| Surface gravity (log g) | ~5 cgs |
| Temperature | 3,500 - 4,000 K |
| Other designations | |
| Kepler-444A: Gaia DR2 2101486923385239808, HIP 94931, LHS 3450, TYC 3129-00329-1, 2MASS J19190052+4138043 | |
| Kepler-444BC: Gaia DR2 2101486923382009472 | |
| Database references | |
| SIMBAD | data |
| B/C | |
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