Abstract

Contributed Talk - Plenary

The First Optical Transmission Spectrum of the inflated Hot Jupiter WASP-168b

Matthew Godfrey
University of Warwick

We present the first optical transmission spectrum of the inflated hot Jupiter WASP-168b, based on four ground-based transits obtained with EFOSC2 and reduced using the Tiberius pipeline. By modelling spot occultations in one transit and applying careful detrending, limb-darkening treatment, and systematic corrections, we recover a high-precision transmission spectrum from which no strong sodium absorption is detected, indicating that clouds or hazes are muting atomic features at these altitudes. WASP-168b’s grazing geometry introduces strong degeneracies, making it a valuable test case for developing robust transmission-spectroscopy techniques suited to high-impact-parameter systems. This work provides the first atmospheric constraints for WASP-168b and refines key system parameters beyond the discovery paper, demonstrating the capability of ground-based facilities to characterise challenging systems.