K2-22b (also known as EPIC 201637175 b) is an exoplanet 801 ly from Earth, rapidly orbiting the red dwarfK2-22 with an orbital period of 9.145872 hours.[2] It has a mass of 0.02 ME and a radius below 0.71 ME.[3] 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 0.02ME, and the planet will be gone in 21 million years in future.[3]
^Adams, Elisabeth R.; Jackson, Brian; Johnson, Samantha; Ciardi, David R.; Cochran, William D.; Endl, Michael; Everett, Mark E.; Furlan, Elise; Howell, Steve B.; Jayanthi, Prasanna; MacQueen, Phillip J.; Matson, Rachel A.; Partyka-Worley, Ciera; Schlieder, Joshua; Scott, Nicholas J.; Stanton, Sevio M.; Ziegler, Carl (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, arXiv:2011.11698
