Exploring the Diversity of Jupiter-Class Planets (Discussion Meeting Contribution)

Abstract

Royal Society Discussion Meeting (2013) `Characterizing exoplanets'. Of the 900+ confirmed exoplanets discovered since 1995 for which we have constraints on their mass (i.e., not including Kepler candidates), 75% have masses larger than Saturn (0.3MJ), 53% are more massive than Jupiter, and 67% are within 1 AU of their host stars. And yet the term `hot Jupiter' fails to account for the incredible diversity of this class of object, which exists on a continuum of giant planets from the cool jovians of our own solar system to the highly-irradiated, tidally-locked hot roasters. We review theoretical expectations for the temperatures, molecular composition and cloud properties of Jupiter-class objects under a variety of different conditions. We discuss the classification schemes for these Jupiter-class planets proposed to date, including the implications for our own Solar System giant planets and the pitfalls associated with classification at this early stage of exoplanetary spectroscopy. We discuss the range of planetary types described by previous authors, accounting for: (i) thermochemical equilibrium expectations for cloud condensation and favoured chemical stability fields; (ii) the metallicity and formation mechanism for these giant planets; (iii) the importance of optical absorbers for energy partitioning and the generation of a temperature inversion; (iv) the favoured photochemical pathways and expectations for minor species (e.g., saturated hydrocarbons and nitriles); (v) the unexpected presence of molecules due to vertical mixing of species above their quench levels; and (vi) methods for energy and material redistribution throughout the atmosphere (e.g., away from the highly irradiated daysides of close-in giants). Finally, we will discuss the benefits and flaws of retrieval techniques for establishing a family of atmospheric solutions that reproduce the available data.

Royal Society Theo Murphy Discussion Meeting (2013) `Characterizing exoplanets: detection, formation, interiors, atmospheres and habitability'.Fletcher LN, Irwin PGJ, Barstow JK, de Kok RJ, Lee J-M, Aigrain S. 2014, Exploring the diversity of Jupiter-class planets. Phil. Trans. R. Soc. A 20130064

References in corpus (9)

• Detection of atmospheric haze on an extrasolar planet: The 0.55 - 1.05 micron transmission spectrum of HD189733b with the Hubble Space Telescope
• Atmospheric Retrieval for Super-Earths: Uniquely Constraining the Atmospheric Composition with Transmission Spectroscopy
• Can TiO Explain Thermal Inversions in the Upper Atmospheres of Irradiated Giant Planets?
• Atmospheric Sulfur Photochemistry on Hot Jupiters
• Theoretical Spectral Models of the Planet HD 209458b with a Thermal Inversion and Water Emission Bands
• A comparison of chemistry and dust cloud formation in ultracool dwarf model atmospheres
• Theory for the Secondary Eclipse Fluxes, Spectra, Atmospheres, and Light Curves of Transiting Extrasolar Giant Planets
• Physical parameters of two very cool T dwarfs
• The source of widespread 3-$\mu$m absorption in Jupiter's clouds: Constraints from 2000 Cassini VIMS observations

Cited by in corpus (2)

• Highlights in the Study of Exoplanet Atmospheres
• Atmospheric Regimes and Trends on Exoplanets and Brown Dwarfs