Transmission spectroscopy with VLT FORS2: a featureless spectrum for the low-density transiting exoplanet WASP-88b

Petros Spyratos, Nikolay Nikolov, John Southworth, Savvas Constantinou, Nikku Madhusudhan, Aarynn L Carter, Ernst J W de Mooij, Jonathan J Fortney, Neale P Gibson, Jayesh M Goyal, Christiane Helling, Nathan J Mayne, Thomas Mikal-Evans

Research output: Contribution to journalArticlepeer-review

2 Downloads (Pure)

Abstract

We present ground-based optical transmission spectroscopy of the low-density hot Jupiter WASP-88b covering the wavelength range 4413 − 8333 Å with the FORS2 spectrograph on the Very Large Telescope. The FORS2 white light curves exhibit a significant time-correlated noise which we model using a Gaussian Process and remove as a wavelength-independent component from the spectroscopic light curves. We analyse complementary photometric observations from the Transiting Exoplanet Survey Satellite and refine the system properties and ephemeris. We find a featureless transmission spectrum with increased absorption towards shorter wavelengths. We perform an atmospheric retrieval analysis with the aura code, finding tentative evidence for haze in the upper atmospheric layers and a lower likelihood for a dense cloud deck. Whilst our retrieval analysis results point toward clouds and hazes, further evidence is needed to definitively reject a clear-sky scenario.
Original languageEnglish
Pages (from-to)2853–2870
JournalMonthly Notices of the Royal Astronomical Society
Volume506
Issue number2
DOIs
Publication statusPublished - 05 Jul 2021

Keywords

  • Space and Planetary Science
  • Astronomy and Astrophysics

Fingerprint

Dive into the research topics of 'Transmission spectroscopy with VLT FORS2: a featureless spectrum for the low-density transiting exoplanet WASP-88b'. Together they form a unique fingerprint.

Cite this