Mass Loss from the Atmosphere of the Planet TOI-1442 c

Abstract

The properties of the planetary system TOI-1422, in which two planets of a neptune type orbit around a low-activity star of solar type with an age of about 5 billion years, are examined. We have previously analyzed activity of the star TOI-1422, found indications of the existence of possible activity cycles, and considered estimates of the orbital rotation period P of the star. The inner planet TOI-1422 b belongs to the hot-neptune types; it rotates with an orbit of period about 13 days and has an equilibrium temperature of Teq,b = 867 K. Calculations using a model of atmospheric loss with an energy limit for TOI-1422 b yielded 9.4·10⁸ g/s of matter from the atmosphere. The outer planet of the system TOI-1422 c can also be regarded as a hot neptune; it has an orbital period of 29.3 days, its minimal mass, Mc sini, is 11.1M _⊕ , and the equilibrium temperature is Teq,c = 661 K. For estimating the radius of TOI-1422 c we have used an empirical M-R relation. It was found that the loss of matter from the atmosphere of the planet TOI-1422 c is 7.8·10⁷ g/s and, given the error in the parameters, it may lie within a range from 6.1·10⁷ g/s to 9.7·10⁷ g/s.