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A reanalysis of the LHS 1140 b atmosphere observed with the Hubble Space Telescope by Biagini, Alfredo; Cracchiolo, Gianluca; Petralia, Antonino; Maldonado, Jesús; Di Maio, Claudia; Micela, Giuseppina is a scholarly article available to read on EtoBox.

What is A reanalysis of the LHS 1140 b atmosphere observed with the Hubble Space Telescope about?

The super-Earth LHS 1140 b is an interesting target for atmospheric observations since it is close to the habitable zone of its star and falls in the gap of the radius distribution of small exoplanets, in the region thought to correspond to the transition between planets with and without atmospheres. Observations of the primary transit with WFC3 on board of the Hubble Space Telescope (HST) revealed a modulation in the planet transmission spectrum compatible with the presence of water; however this modulation may be also due to stellar activity-related phenomena. Here we present a detailed analysis of the WFC3/HST observations to probe the nature of this modulation and to understand if it can be attributable to the presence of unocculted spots on the stellar surface. Our analysis strongly suggests that LHS1140 is a rather quiet star with subsolar [Fe/H] and enriched in alpha elements. Therefore, we rule out the possibility that the planetary spectrum is affected by the presence of spots and faculae. This analysis shows the importance of a proper modelling of the stellar spectrum when analyzing transit observations. Finally, we modelled the planetary atmosphere of LHS1140 b to retrie

Author

Biagini, Alfredo; Cracchiolo, Gianluca; Petralia, Antonino; Maldonado, Jesús; Di Maio, Claudia; Micela, Giuseppina

Published

2024

Language

EN