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.[2]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cancer |
| Right ascension | 08h 50m 05.67s |
| Declination | +23° 11′ 33.36″ |
| Apparent magnitude (V) | 12.864 (Kepler magnitude)[2] |
| Characteristics | |
| Spectral type | G |
| Astrometry | |
| Proper motion (μ) | RA: -11.864 mas/yr Dec.: -30.702 mas/yr |
| Parallax (π) | 2.9939 ± 0.0510 mas[3] |
| Distance | 1,090 ± 20 ly (334 ± 6 pc) |
| Details | |
| Mass | 0.966999 +0.025227 −0.024169[1] M☉ |
| Radius | 0.894913 +0.041087 −0.025505[1] R☉ |
| Temperature | 5477 ± 50[2] K |
| Metallicity [Fe/H] | +0.26 ± 0.08[2] dex |
| Other designations | |
EPIC 212157262, K2-187, WISE J085005.65+231133.0, 2MASS J08500566+2311333 | |
| Database references | |
| SIMBAD | data |
Planetary system
editK2-187 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🜨 |
References
edit- ^ a b c d "K2-187 PLANET HOST OVERVIEW PAGE". NASA Exoplanet Archive. Retrieved 2018-03-05.
- ^ a b c d e "Andrew W. Mayo" (PDF).
- ^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ Livingston, John H.; Crossfield, Ian J. M.; Petigura, Erik A.; Gonzales, Erica J.; Ciardi, David R.; Beichman, Charles A.; Christiansen, Jessie L.; Dressing, Courtney D.; Henning, Thomas; Howard, Andrew W.; Isaacson, Howard; Fulton, Benjamin J.; Kosiarek, Molly; Schlieder, Joshua E.; Sinukoff, Evan; Tamura, Motohide (2018). "Sixty Validated Planets from K2 Campaigns 5–8". The Astronomical Journal. 156 (6): 277. arXiv:1810.04074. Bibcode:2018AJ....156..277L. doi:10.3847/1538-3881/aae778. S2CID 119387939.