K2-187
Sun-like star in the constellation Cancer
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K2-187, also known as EPIC 212157262, is a Sun-like star in K2 Campaign 5. It is very close in size and temperature to the Sun, and has a system of four confirmed exoplanets ranging between 1.4 R🜨 and 3.2 R🜨. The innermost planet takes just 18 hours to orbit its star, while the outermost planet orbits every 2 weeks.[6]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cancer[1] |
| Right ascension | 08h 50m 05.668s[2] |
| Declination | +23° 11′ 33.36″[2] |
| Apparent magnitude (V) | 13.081[3] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | G7[4] |
| Astrometry | |
| Proper motion (μ) | RA: −11.872[2] mas/yr Dec.: −30.597[2] mas/yr |
| Parallax (π) | 3.0740±0.0192 mas[2] |
| Distance | 1,061 ± 7 ly (325 ± 2 pc) |
| Details | |
| Mass | 0.967+0.025 −0.024[5] M☉ |
| Radius | 0.895+0.041 −0.026[5] R☉ |
| Luminosity | 0.62[4] L☉ |
| Temperature | 5,477±50[6] K |
| Metallicity [Fe/H] | +0.26±0.08[6] dex |
| Rotation | 20.34 days[7] |
| Rotational velocity (v sin i) | 45[8] km/s |
| Age | 1.85[9] Gyr |
| Other designations | |
| EPIC 212157262, K2-187, WISE J085005.65+231133.0, 2MASS J08500566+2311333 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
Planetary system
K2-187 has at least four orbiting exoplanets: two Super-Earths, one Hot Neptune, and one Mini-Neptune. All four planets are in near-resonances with each other and are far too hot for life.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | — | 0.016322 | 0.773981+0.000052 −0.000050 |
— | 81.930168+5.825258 −11.735217° |
1.30+0.13 −0.13 R🜨 |
| c | — | 0.0391185 | 2.871788+0.000256 −0.000257 |
— | 86.067367+2.836604 −6.998926° |
1.80+0.14 −0.14 R🜨 |
| d | — | 0.0718533 | 7.149079+0.000360 −0.000372 |
— | 87.483206+1.886985 −3.903548° |
3.17+0.18 −0.18 R🜨 |
| e | — | 0.11036 | 13.608341+0.001661 −0.001580 |
— | 88.970197+0.751147 −1.318388° |
2.38+0.18 −0.18 R🜨 |