Detalles de publicación
PP 020047
Can we detect the stellar differential rotation of WASP-7 through the Rossiter-McLaughlin observations?
(1)Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, PT4150-762 Porto, Portugal, (2) Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua Campo Alegre, 4169-007 Porto, Portugal, (3) Institut für Astrophysik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany, (4)Observatoire de Genève, Université de Genève, 51 Chemin des Maillettes, Versoix 1290, Switzerland, (5) Instituto de Astrofísica de Canarias (IAC), E-38200 La Laguna, Tenerife, Spain
The Rossiter-McLaughlin (RM) effect is the radial velocity signal generated when an object
transits a rotating star. Stars rotate differentially and this affects the shape and amplitude of this
signal, on a level that can no longer be ignored with precise spectrographs. Highly misaligned
planets provide a unique opportunity to probe stellar differential rotation via the RM effect, as
they cross several stellar latitudes. In this sense, WASP-7, and its hot Jupiter with a projected
misalignment of ∼ 90 degree , is one of the most promising targets. The aim of this work is to
understand if the stellar differential rotation is measurable through the RM signal for systems
with a geometry similar to WASP-7. In this sense, we use a modified version of SOAP3.0 to
explore the main hurdles that prevented the precise determination of the differential rotation of
WASP-7. We also investigate whether the adoption of the next generation spectrographs, like
ESPRESSO, would solve these issues. Additionally, we assess how instrumental and stellar
noise influence this effect and the derived geometry of the system. We found that, for WASP7, the white noise represents an important hurdle in the detection of the stellar differential
rotation, and that a precision of at least 2 m s−1 or better is essential.
transits a rotating star. Stars rotate differentially and this affects the shape and amplitude of this
signal, on a level that can no longer be ignored with precise spectrographs. Highly misaligned
planets provide a unique opportunity to probe stellar differential rotation via the RM effect, as
they cross several stellar latitudes. In this sense, WASP-7, and its hot Jupiter with a projected
misalignment of ∼ 90 degree , is one of the most promising targets. The aim of this work is to
understand if the stellar differential rotation is measurable through the RM signal for systems
with a geometry similar to WASP-7. In this sense, we use a modified version of SOAP3.0 to
explore the main hurdles that prevented the precise determination of the differential rotation of
WASP-7. We also investigate whether the adoption of the next generation spectrographs, like
ESPRESSO, would solve these issues. Additionally, we assess how instrumental and stellar
noise influence this effect and the derived geometry of the system. We found that, for WASP7, the white noise represents an important hurdle in the detection of the stellar differential
rotation, and that a precision of at least 2 m s−1 or better is essential.