A detailed spectropolarimetric analysis of the planet hosting star WASP-12 - Astrophysics > Solar and Stellar AstrophysicsReport as inadecuate

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Abstract: The knowledge of accurate stellar parameters is paramount in several fieldsof stellar astrophysics, particularly in the study of extrasolar planets, whereoften the star is the only visible component and therefore used to infer theplanet-s fundamental parameters. Another important aspect of the analysis ofplanetary systems is the stellar activity and the possible star-planetinteraction. Here we present a self-consistent abundance analysis of the planethosting star WASP-12 and a high-precision search for a structured stellarmagnetic field on the basis of spectropolarimetric observations obtained withthe ESPaDOnS spectropolarimeter. Our results show that the star does not have astructured magnetic field, and that the obtained fundamental parameters are ingood agreement with what was previously published. In addition we deriveimproved constraints on the stellar age 1.0-2.65 Gyr, mass 1.23-1.49 M-M0,and distance 295-465 pc. WASP-12 is an ideal object to look for pollutionsignatures in the stellar atmosphere. We analyse the WASP-12 abundances as afunction of the condensation temperature and compare them with those publishedby several other authors on planet hosting and non-planet hosting stars. Wefind hints of atmospheric pollution in WASP-12-s photosphere, but are unable toreach firm conclusions with our present data. We conclude that a differentialanalysis based on WASP-12 twins will probably clarify if an atmosphericpollution is present, the nature of this pollution and its implications in theplanet formation and evolution. We attempt also the direct detection of thecircumstellar disk through infrared excess, but without success.

Author: L. Fossati, S. Bagnulo, A. Elmasli, C. A. Haswell, S. Holmes, O. Kochukhov, E. L. Shkolnik, D. V. Shulyak, D. Bohlender, B. Albay

Source: https://arxiv.org/

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