CCAPP Seminar: "Spin-Orbit Misalignments of Planets around Hot Stars as a Tracer of Planet Migration" Marshall Johnson (OSU Astronomy)

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June 12, 2018
11:30AM - 12:30PM
Location
PRB 4138

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Add to Calendar 2018-06-12 11:30:00 2018-06-12 12:30:00 CCAPP Seminar: "Spin-Orbit Misalignments of Planets around Hot Stars as a Tracer of Planet Migration" Marshall Johnson (OSU Astronomy) Hot stars (mid-F type and earlier) typically rotate rapidly, due to their lack of deep surface convective zones. Hot Jupiters around these stars often have orbits that are highly misaligned with respect to the stellar rotation, which has been attributed to weak tidal damping in the shallow convective zone. The distribution of spin-orbit misalignments of planets around hot stars therefore encodes information about whatever mechanisms--likely related to planet migration--originally generated the misalignments. Spin-orbit misalignments are also easier to measure for planets around rapidly rotating stars. Planets around hot stars are therefore an ideal population for spin-orbit misalignment measurements. I will present new spin-orbit misalignment measurements obtained using Doppler tomography, where I spectroscopically resolve the line profile perturbation during the transit due to the Rossiter-McLaughlin effect, as well as first results from a new survey to identify close stellar companions to hot stars hosting hot Jupiters. Taken together with results from the literature, the sample of hot Jupiters around hot stars with spin-orbit misalignment measurements is now large enough to begin to determine which mechanism(s) are responsible for the generation of spin-orbit misalignments. I will present initial results from this statistical analysis, and discuss implications for the planet migration processes that emplace hot Jupiters where we observe them today. PRB 4138 Center for Cosmology and AstroParticle Physics (CCAPP) ccapp@osu.edu America/New_York public
Description

Hot stars (mid-F type and earlier) typically rotate rapidly, due to their lack of deep surface convective zones. Hot Jupiters around these stars often have orbits that are highly misaligned with respect to the stellar rotation, which has been attributed to weak tidal damping in the shallow convective zone. The distribution of spin-orbit misalignments of planets around hot stars therefore encodes information about whatever mechanisms--likely related to planet migration--originally generated the misalignments. Spin-orbit misalignments are also easier to measure for planets around rapidly rotating stars. Planets around hot stars are therefore an ideal population for spin-orbit misalignment measurements. I will present new spin-orbit misalignment measurements obtained using Doppler tomography, where I spectroscopically resolve the line profile perturbation during the transit due to the Rossiter-McLaughlin effect, as well as first results from a new survey to identify close stellar companions to hot stars hosting hot Jupiters. Taken together with results from the literature, the sample of hot Jupiters around hot stars with spin-orbit misalignment measurements is now large enough to begin to determine which mechanism(s) are responsible for the generation of spin-orbit misalignments. I will present initial results from this statistical analysis, and discuss implications for the planet migration processes that emplace hot Jupiters where we observe them today.

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