Abstract

Contributed Talk - Splinter ExoPlanets

Tuesday, 16 September 2025, 15:53

What a Hell ?! Deducing interior properties of 55 CNC e from LBT observations

Engin Keles
Freie Universität Berlin

Recent discoveries have confirmed the presence of rocky worlds in close orbits with high surface temperatures, enabling the surface rock to melt, a phenomenon known as lava worlds. For such planets, the preferred atmospheric scenario proposes a permanent magma ocean on the planet's surface that builds up an extended thin silicate-vapor atmosphere, with the properties of the latter defined by the composition of the former. One target of interest to deduce the atmospheric conditions is the super-Earth 55 CNC e, which might possess a significant atmosphere inferred from one JWST eclipse observation, however, being not confirmed by several other JWST data sets. High-resolution transmission spectroscopy enables us to infer the atmospheres of exoplanets from the ground, giving a complementary view to low-resolution JWST investigations. We present several transit observations of 55 CNC e observed at the Large-Binocular-Telescope with the high-resolution spectrograph PEPSI. As PEPSI can observe in the optical wavelength range at different spectral resolution modes, we gathered transit observations at R = 50 000, 130 000, and 250 000. Comparing the observations to interior-atmosphere models and searching for different atmospheric atomic and molecular absorption signatures, we will provide preliminary insights from our observations of this lava world.