Modeling of Hot Jupiter HAT-P-32b and Transit Absorptions in Excited Hydrogen and Helium Atom Lines

Abstract

The results of absorption modeling in the hydrogen Hα 6563 Å and helium 10830 Å lines for hot Jupiter HAT‑P-32b have been presented. The modeling has been performed using a three-dimensional hydrodynamic code together with the Monte Carlo model of Lyα photon transport. A wide range of stellar radiation and atmospheric parameters has been considered. It has been found that the measured spectrally resolved transit absorption in both lines can be well described by model calculations with the stellar radiation in the XUV range limited to 200 erg/cm²/s per 1 AU, the helium content in the planet’s atmosphere is He/H = 2/98, and metallicity is [Fe/H] = –1. It has been shown that absorption in the helium line occurs uniformly in a large volume of the outflowing atmosphere, and in the hydrogen line, it occurs in a layer of 1.5–2.75 planet radii.