Europlanet Science Congress 2021
Virtual meeting
13 – 24 September 2021
Europlanet Science Congress 2021
Virtual meeting
13 September – 24 September 2021
EPSC Abstracts
Vol. 15, EPSC2021-700, 2021
European Planetary Science Congress 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Novel methods to probe exoplanet atmospheres using ground-based spectrophotometry

Vatsal Panwar1, Jean-Michel Desert1, Kamen Todorov1, Jacob Bean2, Catherine Huitson3, Kevin Stevenson4, Jonathan Fortney5, and Marcel Bergmann6
Vatsal Panwar et al.
  • 1University of Amsterdam, Amsterdam, Netherlands
  • 2Department of Astronomy and Astrophysics, University of Chicago, Chicago, USA
  • 3CASA, University of Colorado, Boulder, USA
  • 4Applied Physics Laboratory, Johns Hopkins University, Laurel, USA
  • 5Department of Astronomy and Astrophysics, University of California, Santa Cruz, USA
  • 6NOAO Gemini Observatory, present address Palo Alto, CA, USA

Ground-based spectrophotometric observations of transiting exoplanet atmospheres conventionally rely on correcting for instrumental and telluric systematics in the light curves by using reference stars that are simultaneously observed. However, this approach often leads to sub-optimal corrections due to multiple accounts on which the target and reference star spectra can be affected by systematics differently through the night, ultimately limiting the achievable precision and accuracy on the measurement of planetary atmospheric signatures. We introduce a new method based on Gaussian Processes regression to address this challenge by extracting the transmission or emission spectrum without relying explicitly on the reference stars. Our new method overcomes the necessity of using reference stars and opens up the doors to ground-based atmospheric observations of exoplanets orbiting bright host stars (e.g. those discovered by TESS) that intrinsically lack proper reference stars. We present results from the application of our method to a broad sample of exoplanets observed in the optical and near-infrared using Gemini/GMOS and Keck/MOSFIRE. We also discuss the challenges and possible solutions arising from stellar variability towards combining high precision ground-based low-resolution spectroscopy observations in complementarity with future infrared observations from HST and JWST.

How to cite: Panwar, V., Desert, J.-M., Todorov, K., Bean, J., Huitson, C., Stevenson, K., Fortney, J., and Bergmann, M.: Novel methods to probe exoplanet atmospheres using ground-based spectrophotometry, European Planetary Science Congress 2021, online, 13–24 Sep 2021, EPSC2021-700,, 2021.

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