Astronomy:K2-22b

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K2-22b
Discovery[1]
Discovery siteKepler Space Observatory
Discovery date2015
Transit
Orbital characteristics
0.0088 AU (1,320,000 km)
Eccentricitynull[2]
Orbital period0.381078[2] d
Inclinationnull[2]
StarK2-22
Physical characteristics
Mean radius<0.71R[3]
Mass0.02 M[3]
Physics2,100 K (1,830 °C; 3,320 °F)


K2-22b (also known as EPIC 201637175 b) is an exoplanet 801 ly from Earth, rapidly orbiting the red dwarf K2-22 with an orbital period of 9.145872 hours.[2] It has a mass below 445 Me and a radius below 2.5 Re. The planet was not detected in the K2 photometry. K2 photometry reveals the presence of an anomalous light curve consistent with evaporation of dust from the planet. This dust forms a tail both ahead and behind the planet, similar to some comets in the Solar System.[1] The evaporation of this dust requires a low surface gravity from the host planet, implying it is a low mass, "Mars, Mercury, or even lunar sized bodies with surface gravities of 1/6 to 1/3 that of Earth are to be preferred."[1]

The survey in 2020 has failed to validate the existence of the planet, although did not claim it to be a false positive.[4]

The observation of planetary system in 2021 has failed to detect the planet itself, placing an upper limit of 0.71R on its size. With the observed mass loss rate, the probable planet mass is 0.02M, and the planet will be gone in 21 million years in future.[3]

See also

References

  1. 1.0 1.1 1.2 Sanchis-Ojeda, R. et al. (2015). "The K2-ESPRINT Project I: Discovery of the Disintegrating Rocky Planet K2-22b with a Cometary Head and Leading Tail". The Astrophysical Journal 812 (2): 112. doi:10.1088/0004-637X/812/2/112. Bibcode2015ApJ...812..112S. 
  2. 2.0 2.1 2.2 2.3 "K2-22 b CONFIRMED PLANET OVERVIEW PAGE". NASA Exoplanet Archive. http://exoplanetarchive.ipac.caltech.edu/cgi-bin/DisplayOverview/nph-DisplayOverview?objname=K2-22+b&type=CONFIRMED_PLANET. 
  3. 3.0 3.1 3.2 Schlawin, Everett; Su, Kate Y. L.; Herter, Terry; Ridden-Harper, Andrew; Apai, Dániel (2021), "LBT Reveals Large Dust Particles and a High Mass-loss Rate for K2-22 B", The Astronomical Journal 162 (2): 57, doi:10.3847/1538-3881/ac0b41, Bibcode2021AJ....162...57S 
  4. Adams, Elisabeth R.; Jackson, Brian; Johnson, Samantha; Ciardi, David R.; Cochran, William D.; Endl, Michael; Everett, Mark E.; Furlan, Elise et al. (2020), ULTRA SHORT PERIOD PLANETS IN K2 III: NEIGHBORS ARE COMMON WITH 12 NEW MULTI-PLANET SYSTEMS AND 26 NEWLY VALIDATED PLANETS IN CAMPAIGNS 0-8, 10