Mass loss rate and local thermodynamic state of KELT-9 b thermosphere from the hydrogen Balmer series

A. Wyttenbach, P. Mollière, D. Ehrenreich +12

KELT-9 b, the hottest known exoplanet with $T\sim 4400$ K, is the archetype of a new planet class known as ultra-hot Jupiters. These exoplanets are presumed to have an atmosphere do…