Evaporation of extrasolar planets

TL;DR

This paper reviews observational evidence and models of atmospheric evaporation in extrasolar giant planets, focusing on hydrogen escape from HD209458b, and discusses implications for exoplanet studies.

Contribution

It synthesizes current observations and models of atmospheric evaporation in exoplanets, highlighting hydrogen escape as a key signature and discussing broader implications.

Findings

Hydrogen escape detected from HD209458b's atmosphere

The planet's upper atmosphere is actively evaporating

Implications for exoplanet atmospheric evolution

Abstract

Atomic hydrogen escaping from the extrasolar giant planet HD209458b provides the largest observational signature ever detected for an extrasolar planet atmosphere. In fact, the upper atmosphere of this planet is evaporating. Observational evidences and interpretations coming from various models are reviewed. Implications for exoplanetology are discussed.