Presentation #102.88 in the session Poster Session.
The intense equilibrium temperature of ultra-hot Jupiters drives the atmospheres of these exoplanets to extremes, with substantial atomic and ionised components, and extreme atmospheric dynamics. The hottest of these exoplanets known today is KELT-9b, an immensely irradiated planet orbiting its A-type host star in less than 1.5 days. Using several transit observations with different optical and infrared spectrographs, we apply the cross-correlation technique to detect atomic and molecular absorption in KELT9-b’s atmosphere. The combination of the contributions from different wavelength ranges provided by different spectrographs expands the potential to search for a large variety of chemical species, which may have lines spanning wide ranges. We combine the signals by considering the expected flux contribution caused by the wavelength restrictions, and the measured noise of these instruments. Our efforts have resulted in the detections of heavy elements never previously seen in KELT9-b’s atmosphere (Sr II, Ni I, V I), and some never detected in the atmosphere of any exoplanet (La II, Ba II, Rb I). Furthermore, we demonstrate that signals of atomic iron and other metals can constrain the temperature profile of the planet’s terminator and optimise search methods enabling the detection of less abundant species. The success of this project validates the utility of combining spectroscopic observations as a powerful lens to explore the atmospheres of ultra-hot Jupiters in greater detail.