ES-03-0009

Unlocking the Day-side of Ultra Hot Jupiters: A NIR High-Resolution Emission Spectroscopy Study of WASP-33b

Stevanus Kristianto Nugroho, Ernst de Mooij, Neale Gibson, Hajime Kawahara, Vivien Parmentier, Teruyuki Hirano, Masayuki Kuzuhara, Matteo Brogi, Jayne Birkby, Motohide Tamura, Yui Kawashima, Takayuki Kotani, Kento Masuda, Christopher Watson, Konstanze Zwintz, Sayyed Ali Rafi, IRD Team -

High-resolution cross-correlation spectroscopy has been used widely in characterising the atmosphere of exoplanets. It relies on resolving the Doppler-shifted atomic/molecular bands in the spectrum of an exoplanet into individual absorption lines and combining them through cross-correlation to identify the atomic/molecular signatures unambiguously. Using this technique, we analysed high-resolution emission spectra of the day-side of an ultra-hot Jupiter, WASP-33b, taken using the InfraRed Doppler instrument on the Subaru telescope. As a result, we confirmed our previous detection of OH emission at >9 sigma only after the secondary eclipse. We also confirmed previous detections of Fe I, Si I, and Ti I, and found evidence of the emission of Mg I and Mn I after combining all data sets, which, if confirmed, add more chemical species that are detected on the day-side of an exoplanet. The non-detection of OH before the eclipse is likely due to astrophysical phenomena indicating a different spatial distribution of each chemical species. This highlights the 3-D properties of an exoplanet that needs to be taken into account in characterising its atmosphere.