Title: Observing the Evaporating Atmospheres of Exoplanets in Metastable Helium
Abstract: A majority of the extrasolar planets discovered by transit surveys reside surprisingly close to their host stars, and their atmospheres are so intensely irradiated that they can escape altogether. This critical evolutionary process may play a key role in clearing out the Neptune desert (a dearth of Neptune-mass planets on orbits shorter than five days), but it is relatively unconstrained observationally. The recent discovery of the planetary metastable helium line, which probes tenuous gas near the wind-launching radius, allows us to place some of the first observational constraints on photoevaporation. In this talk, I will first discuss a novel narrowband photometric technique for studying atmospheric outflows using the Wide-field InfraRed Camera (WIRC) at Palomar Observatory. I will then mention some initial results from our survey of atmospheric escape in gas giant planets on the edge of the Neptune desert, as well as some recent constraints on mass loss in the young V1298 Tau system.
I will also discuss how energetic considerations can greatly improve mass-loss inference from helium observations. Finally, I will propose some future directions for atmospheric escape studies.
Host: Jiayin "DJ" Dong
Please email CEHW-SEMINAR-QUESTIONS@lists.psu.edu to register.