Abstract

Ultra-hot Jupiters form a new class of exoplanets that tend to orbit hot early type stars in short periods, and may be heated to temperatures of far over 2,000K on their day-sides. The extreme temperature dissociates all but the most strongly bound molecules and a significant fraction of the atomic gas may be thermally ionised. Under these circumstances, line absorption lines by metals are dominant sources of opacity. We have carried out transit observations of the ultra-hot Jupiter WASP -121 b, revealing a rich spectrum of various metals, including iron and vanadium, but with a notable absence of titanium, which may be depleted due to condensation processes. In this talk I will present our recent observations that target metal emission lines on the planet’s dayside, and demonstrate the power of high-resolution ground-based spectrographs to help us understand global chemical environments of hot exoplanets.