K2-187

K2-187
Observation data; Epoch J2000 Equinox ICRS
Constellation	Cancer
Right ascension	08h 50m 05.668s
Declination	+23° 11′ 33.36″
Apparent magnitude (V)	13.081
Characteristics
Evolutionary stage	Main sequence
Spectral type	G7
Astrometry
Proper motion (μ)	RA: −11.872 mas/yr ; Dec.: −30.597 mas/yr
Parallax (π)	3.0740±0.0192 mas
Distance	1,061 ± 7 ly ; (325 ± 2 pc)
Details
Mass	0.93 M☉
Radius	0.92 R☉
Luminosity	0.62 L☉
Surface gravity (log g)	4.48 cgs
Temperature	5,477±50 K
Metallicity [Fe/H]	+0.26±0.08 dex
Rotation	20.34 days
Rotational velocity (v sin i)	45 km/s
Age	1.85 Gyr
Other designations
	K2-187, EPIC 212157262, 2MASS J08500566+2311333, WISE J085005.65+231133.0
Database references
SIMBAD	data
Exoplanet Archive	data

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 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.

Planetary system

K2-187 has at least four planets: two super-Earths, one hot Neptune, and one sub-Neptune. All four planets are in near-resonances with each other and are too hot for life.

The K2-187 planetary system
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

↑ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.
1 2 3 4 5 6 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
↑ Nascimbeni, V.; Piotto, G.; Ortolani, S.; Giuffrida, G.; Marrese, P. M.; Magrin, D.; Ragazzoni, R.; Pagano, I.; Rauer, H.; Cabrera, J.; Pollacco, D.; Heras, A. M.; Deleuil, M.; Gizon, L.; Granata, V. (2016). "An all-sky catalogue of solar-type dwarfs for exoplanetary transit surveys". Monthly Notices of the Royal Astronomical Society. 463 (4): 4210. arXiv:1609.03037. Bibcode:2016MNRAS.463.4210N. doi:10.1093/mnras/stw2313.
1 2 Hardegree-Ullman, Kevin K.; Zink, Jon K.; Christiansen, Jessie L.; Dressing, Courtney D.; Ciardi, David R.; Schlieder, Joshua E. (2020). "Scaling K2. I. Revised Parameters for 222,088 K2 Stars and a K2 Planet Radius Valley at 1.9 R_⊕". The Astrophysical Journal Supplement Series. 247 (1): 28. arXiv:2001.11511. Bibcode:2020ApJS..247...28H. doi:10.3847/1538-4365/ab7230.
1 2 3 Stassun, Keivan G.; et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467.
1 2 3 4 "Andrew W. Mayo" (PDF). Archived from the original (PDF) on 2018-03-24. Retrieved 2018-03-03.
↑ Reinhold, Timo; Hekker, Saskia (2020). "Stellar rotation periods from K2 Campaigns 0-18. Evidence for rotation period bimodality and simultaneous variability decrease". Astronomy and Astrophysics. 635. arXiv:2001.08214. Bibcode:2020A&A...635A..43R. doi:10.1051/0004-6361/201936887.
↑ Zuo, Fang; Luo, A. -Li; Du, Bing; Li, Yinbi; Jones, Hugh R. A.; Song, Yi-han; Kong, Xiao; Guo, Yan-xin (2024). "Projected Rotational Velocities for LAMOST Stars with Effective Temperatures Lower than 9000 K". The Astrophysical Journal Supplement Series. 271 (1): 4. arXiv:2401.03959. Bibcode:2024ApJS..271....4Z. doi:10.3847/1538-4365/ad1eeb.
↑ Zink, Jon K.; Hardegree-Ullman, Kevin K.; Christiansen, Jessie L.; Petigura, Erik A.; Boley, Kiersten M.; Bhure, Sakhee; Rice, Malena; Yee, Samuel W.; Isaacson, Howard; Fernandes, Rachel B.; Howard, Andrew W.; Blunt, Sarah; Lubin, Jack; Chontos, Ashley; Pidhorodetska, Daria; MacDougall, Mason G. (2023). "Scaling K2. VI. Reduced Small-planet Occurrence in High-galactic-amplitude Stars". The Astronomical Journal. 165 (6): 262. arXiv:2305.13389. Bibcode:2023AJ....165..262Z. doi:10.3847/1538-3881/acd24c.
↑ "K2-187 PLANET HOST OVERVIEW PAGE". NASA Exoplanet Archive. Retrieved 2018-03-05.
↑ 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.

[Roman1987-1] Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.

[dr3-2] 1 2 3 4 5 6 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.

[nascimbeni2016-3] Nascimbeni, V.; Piotto, G.; Ortolani, S.; Giuffrida, G.; Marrese, P. M.; Magrin, D.; Ragazzoni, R.; Pagano, I.; Rauer, H.; Cabrera, J.; Pollacco, D.; Heras, A. M.; Deleuil, M.; Gizon, L.; Granata, V. (2016). "An all-sky catalogue of solar-type dwarfs for exoplanetary transit surveys". Monthly Notices of the Royal Astronomical Society. 463 (4): 4210. arXiv:1609.03037. Bibcode:2016MNRAS.463.4210N. doi:10.1093/mnras/stw2313.

[hu2020-4] 1 2 Hardegree-Ullman, Kevin K.; Zink, Jon K.; Christiansen, Jessie L.; Dressing, Courtney D.; Ciardi, David R.; Schlieder, Joshua E. (2020). "Scaling K2. I. Revised Parameters for 222,088 K2 Stars and a K2 Planet Radius Valley at 1.9 R_⊕". The Astrophysical Journal Supplement Series. 247 (1): 28. arXiv:2001.11511. Bibcode:2020ApJS..247...28H. doi:10.3847/1538-4365/ab7230.

[tic-5] 1 2 3 Stassun, Keivan G.; et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467.

[dtu.dk-6] 1 2 3 4 "Andrew W. Mayo" (PDF). Archived from the original (PDF) on 2018-03-24. Retrieved 2018-03-03.

[reinhold2020-7] Reinhold, Timo; Hekker, Saskia (2020). "Stellar rotation periods from K2 Campaigns 0-18. Evidence for rotation period bimodality and simultaneous variability decrease". Astronomy and Astrophysics. 635. arXiv:2001.08214. Bibcode:2020A&A...635A..43R. doi:10.1051/0004-6361/201936887.

[zuo2024-8] Zuo, Fang; Luo, A. -Li; Du, Bing; Li, Yinbi; Jones, Hugh R. A.; Song, Yi-han; Kong, Xiao; Guo, Yan-xin (2024). "Projected Rotational Velocities for LAMOST Stars with Effective Temperatures Lower than 9000 K". The Astrophysical Journal Supplement Series. 271 (1): 4. arXiv:2401.03959. Bibcode:2024ApJS..271....4Z. doi:10.3847/1538-4365/ad1eeb.

[zink2023-9] Zink, Jon K.; Hardegree-Ullman, Kevin K.; Christiansen, Jessie L.; Petigura, Erik A.; Boley, Kiersten M.; Bhure, Sakhee; Rice, Malena; Yee, Samuel W.; Isaacson, Howard; Fernandes, Rachel B.; Howard, Andrew W.; Blunt, Sarah; Lubin, Jack; Chontos, Ashley; Pidhorodetska, Daria; MacDougall, Mason G. (2023). "Scaling K2. VI. Reduced Small-planet Occurrence in High-galactic-amplitude Stars". The Astronomical Journal. 165 (6): 262. arXiv:2305.13389. Bibcode:2023AJ....165..262Z. doi:10.3847/1538-3881/acd24c.

[NasaExoplanetArchive-10] "K2-187 PLANET HOST OVERVIEW PAGE". NASA Exoplanet Archive. Retrieved 2018-03-05.

[11] 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.