K2-66b is a confirmed[2][3][failed verification]mega-Earth orbiting the subgiant K2-66, about 520 parsecs (1,700 ly) from Earth in the direction of Aquarius.[1] It is an extremely hot and dense planet heavier than Neptune, but with only about half its radius.[4]
Planet properties
Mass, radius, and temperature
K2-66b is a mega-Earth with radius 2.49 R🜨 and mass 21.3 ME.[5] The planet's temperature is highly variable due to the variability of its host star, and is currently estimated at 1,372 K (1,099 °C; 2,010 °F).[2]
Orbit
The planet orbits every 5.07 days at 0.06 AU.[1] It orbits within a "photoevaporation desert", where orbiting exoplanets should be very uncommon.[4][6] K2-66b's orbit is nearly circular.[2][7]
^ abSinukoff, Evan; Howard, Andrew W.; Petigura, Erik A.; Fulton, Benjamin J.; Crossfield, Ian J. M.; Isaacson, Howard; Gonzales, Erica; Crepp, Justin R.; Brewer, John M.; Hirsch, Lea; Weiss, Lauren M.; Ciardi, David R.; Schlieder, Joshua E.; Benneke, Bjoern; Christiansen, Jessie L.; Dressing, Courtney D.; Hansen, Brad M. S.; Knutson, Heather A.; Kosiarek, Molly; Livingston, John H.; Greene, Thomas P.; Rogers, Leslie A.; Lépine, Sébastien (2017). "K2-66b and K2-106b: Two Extremely Hot Sub-Neptune-size Planets with High Densities". The Astronomical Journal. 153 (6): 271. arXiv:1705.03491. Bibcode:2017AJ....153..271S. doi:10.3847/1538-3881/aa725f. S2CID31572527.
^ abFutó, P. (2018). Kepler-145b and K2-66b: A Kepler- and a K2-Mega-Earth with Different Compositional Characteristics. Lunar and Planetary Science Conference. No. 2083. p. 1224. Bibcode:2018LPI....49.1224F.