Observational Consequences of Shallow-water Magnetohydrodynamics on Hot Jupiters

Abstract

We use results of shallow-water magnetohydrodynamics (SWMHD) to place estimates on the minimum magnetic field strengths required to cause atmospheric wind variations (and therefore westward venturing hotspots) for a dataset of hot Jupiters (HJs), including HAT-P-7b, CoRoT-2b, Kepler-76, WASP-12b, and WASP-33b, on which westward hotspots have been observationally inferred. For HAT-P-7b and CoRoT-2b our estimates agree with past results; for Kepler-76b we find that the critical dipolar magnetic field strength, over which the observed wind variations can be explained by magnetism, lies between $4\mbox{ G}$ and $19\mbox{ G}$; for WASP-12b and WASP-33b westward hotspots can be explained by $1\mbox{ G}$ and $2\mbox{ G}$ dipolar fields respectively. Additionally, to guide future observational missions, we identify $61$ further HJs that are likely to exhibit magnetically-driven atmospheric wind variations and predict these variations are highly-likely in $\sim 40$ of the hottest HJs.

10 pages, 3 figures, 2 tables

References in corpus (11)

• Multi-Wavelength Constraints on the Day-Night Circulation Patterns of HD 189733b
• The phase-dependent Infrared brightness of the extrasolar planet upsilon Andromedae b
• Dynamics and Disequilibrium Carbon Chemistry in Hot Jupiter Atmospheres, With Application to HD 209458b
• Hot Nights on Extrasolar Planets: Mid-IR Phase Variations of Hot Jupiters
• Magnetic field strengths of hot Jupiters from signals of star-planet interactions
• Magnetic Effects in Hot Jupiter Atmospheres
• Variability in the Atmosphere of the Hot Giant Planet HAT-P-7 b
• Detection of a Westward Hotspot Offset in the Atmosphere of a Hot Gas Giant CoRoT-2b
• TESS unveils the phase curve of WASP-33b. Characterization of the planetary atmosphere and the pulsations from the star
• Shallow-water Magnetohydrodynamics for Westward Hotspots on Hot Jupiters
• Variability in the Atmosphere of the Hot Jupiter Kepler-76b

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