Pluto's lower atmosphere structure and methane abundance from high-resolution spectroscopy and stellar occultations

  title={Pluto's lower atmosphere structure and methane abundance from high-resolution spectroscopy and stellar occultations},
  author={Emmanuel Lellouch and Bruno Sicardy and Catherine de Bergh and Hans Ulrich Kaufl and Samir Kassi and Alain Campargue},
  journal={Astronomy and Astrophysics},
Context. Pluto possesses a thin atmosphere, primarily composed of nitrogen, in which the detection of methane has been reported. Aims. The goal is to constrain essential but so far unknown parameters of Pluto's atmosphere, such as the surface pressure, lower atmosphere thermal stucture, and methane mixing ratio. Methods. We use high-resolution spectroscopic observations of gaseous methane and a novel analysis of occultation lightcurves. Results. We show that (i) Pluto's surface pressure is… 

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