Europlanet Science Congress 2020
Virtual meeting
21 September – 9 October 2020
Europlanet Science Congress 2020
Virtual meeting
21 September – 9 October 2020
EPSC Abstracts
Vol.14, EPSC2020-812, 2020
https://doi.org/10.5194/epsc2020-812
Europlanet Science Congress 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Metals in the day-side of ultra-hot Jupiter atmospheres: a key test for planetary formation

Lorenzo Pino1, Jean-Michel Désert2, Matteo Brogi3, Valerio Nascimbeni4, Aldo Stefano Bonomo5, Michael Line6, and Antonio Maggio7
Lorenzo Pino et al.
  • 1University of Amsterdam, Anton Pannekoek Institute for Astronomy/INAF Osservatorio Astrofisico di Arcetri, (l.pino@uva.nl)
  • 2University of Amsterdam, Anton Pannekoek Institute for Astronomy
  • 3University of Warwick, Centre for Exoplanets and Habitability
  • 4INAF - Osservatorio Astronomico di Padova
  • 5INAF - Osservatorio Astrofisico di Torino
  • 6Arizona State University, School of Earth & Space Exploration
  • 7INAF - Osservatorio Astronomico di Palermo

Ultra-hot Jupiters (Teq ≥ 2,500 K) are the hottest gaseous giants known. They emerged as ideal laboratories to test theories of atmospheric structure and its link to planet formation. Indeed, because of their high temperatures, (1) they likely host atmospheres in chemical equilibrium and (2) clouds do not form in their day-side. Thousands of lines of refractory elements such as iron, normally inaccessible in planets, can be studied through high spectral resolution emission spectroscopy, providing a first look into the chemistry of refractory elements in exoplanets. In this talk we report the detection of neutral iron in the day-side emission spectrum of KELT-9b (Tday ~ 4,000  K), the first detection of an atomic species in the emission spectrum of an exoplanet, obtained with HARPS-N optical data gathered in the framework of the GAPS collaboration. Our detection unambiguously indicates the presence of a thermal inversion in the atmosphere of the planet. We also present a new technique to extract planetary parameters from the cross-correlation function in a statistically sound framework, which makes possible the combination with information from the planetary continuum that can be obtained with complementary space facilities. This is a crucial step towards the measurement of metal abundances in exoplanets, a quantity that can be compared to predictions of planet formation theories. In the near future, our technique will be extended to cooler exoplanets. In the era of EELTs and JWST, this kind of measurements could ultimately open a new window on exoplanet formation and evolution.

How to cite: Pino, L., Désert, J.-M., Brogi, M., Nascimbeni, V., Bonomo, A. S., Line, M., and Maggio, A.: Metals in the day-side of ultra-hot Jupiter atmospheres: a key test for planetary formation, Europlanet Science Congress 2020, online, 21 September–9 Oct 2020, EPSC2020-812, https://doi.org/10.5194/epsc2020-812, 2020