Characterization of extrasolar planets through transmission spectroscopy

• Applicant: Professor Dr. Jürgen H.M.M. Schmitt
• Subject Area: Astrophysics and Astronomy
• Term: from 2015 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 281454604

In the framework of this funding application we propose to perform transmission spectroscopy of extrasolar planets in the sodium D lines. The sodium D1 and D2 lines are -- normally -- strong absorption lines in the spectrum of a cool star. During the primary transit of a ``Hot Jupiter'' any sodium present in the planetary atmosphere will lead to an additional absorption signal.While originally carried out and pioneered from space, recently a number of ground-based measurements of excess sodium absorption during planetary transits have been published with somewhat controversial results. We propose use our VLT/UVES data on HD189733b and WASP-7b for a thorough investigation of the feasibility of VLT/UVES data for sodium transmission spectroscopy. We propose to study various methods of analysis for the data extraction and preparation, assess the influence of telluric line contamination with various methods and study the possible influence of stellar activity on possible changes in the sodium absorption. Finally we propose to use atmospheric circulation models coupled with a 3D-radiative transfer treatment to compute model sodium transmission curves and compare them to the available observations.

• DFG Programme: Research Grants