Thermal escape from extrasolar giant planets

Tommi T. Koskinen, Panayotis Lavvas, Matthew J. Harris, Roger Yelle

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

The detection of hot atomic hydrogen and heavy atoms and ions at high altitudes around close-in extrasolar giant planets (EGPs) such as HD209458b implies that these planets have hot and rapidly escaping atmospheres that extend to several planetary radii. These characteristics, however, cannot be generalized to all close-in EGPs. The thermal escape mechanism and mass loss rate from EGPs depend on a complex interplay between photochemistry and radiative transfer driven by the stellar UV radiation. In this study, we explore how these processes change under different levels of irradiation on giant planets with different characteristics. We confirm that there are two distinct regimes of thermal escape from EGPs, and that the transition between these regimes is relatively sharp. Our results have implications for thermal mass loss rates from different EGPs that we discuss in the context of currently known planets and the detectability of their upper atmospheres.

Original languageEnglish (US)
Article number20130089
JournalPhilosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
Volume372
Issue number2014
DOIs
StatePublished - Apr 28 2014

Fingerprint

Planets
escape
planets
Atmosphere
Detectability
Radiative Transfer
Irradiation
Hydrogen
Radius
Radiation
Distinct
Imply
Upper atmosphere
Hot Temperature
Photochemical reactions
Radiative transfer
upper atmosphere
high altitude
Ultraviolet radiation
photochemical reactions

Keywords

  • Atmospheric physics
  • Extrasolar planets
  • Hydrodynamics

ASJC Scopus subject areas

  • Mathematics(all)
  • Physics and Astronomy(all)
  • Engineering(all)

Cite this

Thermal escape from extrasolar giant planets. / Koskinen, Tommi T.; Lavvas, Panayotis; Harris, Matthew J.; Yelle, Roger.

In: Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 372, No. 2014, 20130089, 28.04.2014.

Research output: Contribution to journalArticle

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