Transmission spectroscopy can constrain the properties of the atmospheres of transiting exoplanets. During a transit, in fact, the light blocked from the atmosphere of the planet leaves an imprint in the light coming from the star. This has been shown for many exoplanets with different techniques.
I will introduce chromatic line-profile tomography as a new method to investigate exoplanetary atmospheres: the signal imprinted on the cross-correlation function by a planet transiting its star is in fact dependent on the planet-to-star radius ratio.
I will show the application of this technique to three HARPS transit observations of HD 189733b. Using separately the different orders of the echelle spectrograph, it is possible to obtain a good-quality broadband transmission spectrum of the planet, that is in agreement with the spectra obtained with other techniques.
15 June 2016, 13:30
Centro de Astrofísica
Rua das Estrelas