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, EPSC2020-253, 2020
https://doi.org/10.5194/epsc2020-253
Europlanet Science Congress 2020
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Search for helium in the upper atmosphere of the hot Jupiter WASP-127 b using Phoenix/Gemini

Leonardo A. dos Santos1, David Ehrenreich1, Vincent Bourrier1, Romain Allart1, George King2,3, Monika Lendl1,4, Christophe Lovis1, Steve Margheim5, Jorge Meléndez6, Julia V. Seidel1, and Sérgio G. Sousa7
Leonardo A. dos Santos et al.
  • 1University of Geneva, Faculty of Science, Astronomy Department, Versoix, Switzerland (leonardo.dossantos@unige.ch)
  • 2Department of Physics, University of Warwick, Coventry, UK
  • 3Centre for Exoplanets and Habitability, University of Warwick, Coventry, UK
  • 4Space Research Institute, Austrian Academy of Sciences, Graz, Austria
  • 5Gemini Observatory, La Serena, Chile
  • 6Universidade de São Paulo, Departamento de Astronomia do IAG/USP, São Paulo, Brazil
  • 7Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Porto, Portugal

Large-scale exoplanet search surveys have shown evidence that atmospheric escape is a ubiquitous process that shapes the evolution and demographics of planets. However, we lack a detailed understanding of this process because very few exoplanets discovered to date could be probed for signatures of atmospheric escape. Recently, the metastable helium triplet at 1.083 μm has been shown to be a viable window for the presence of He-rich escaping envelopes around short-period exoplanets. Our objective is to use, for the first time, the Phoenix spectrograph to search for helium in the upper atmosphere of the inflated hot Jupiter WASP-127 b. We observed one transit and reduced the data manually since there is no pipeline available. We did not find a significant in-transit absorption signal indicative of the presence of helium around WASP-127 b, and set a 90% confidence upper limit for excess absorption at 0.87% in a 0.75 Å passband covering the He triplet. Given the large scale height of this planet, the lack of a detectable feature is likely due to unfavorable photoionization conditions to populate the metastable He I triplet. This conclusion is supported by the inferred low coronal and chromospheric activity of the host star and the old age of the system, which result in a relatively mild high-energy environment around the planet.

How to cite: dos Santos, L. A., Ehrenreich, D., Bourrier, V., Allart, R., King, G., Lendl, M., Lovis, C., Margheim, S., Meléndez, J., Seidel, J. V., and Sousa, S. G.: Search for helium in the upper atmosphere of the hot Jupiter WASP-127 b using Phoenix/Gemini, Europlanet Science Congress 2020, online, 21 Sep–9 Oct 2020, EPSC2020-253, https://doi.org/10.5194/epsc2020-253, 2020.