Title:  Technologies for Precision Stellar Activity and Robust Exoplanet Atmospheres

Abstract: The prospect of discovering habitable exoplanet atmospheres hinges on technological innovation across a huge range of modern astrophysics.  Our instruments have to be bigger and better, our knowledge of stellar activity increasingly precise, and our exoplanet atmosphere models ever more accurate.  This talk highlights advances in these three frontiers.
Silicon immersion grating technology has unlocked a new category of high-grasp ground-based near-IR echelle spectrographs such as IGRINS and iSHELL.  Bite-sized Silicon grisms are now operating in JWST NIRCAM, and will enable compact space-based instrument designs ideal for future smallsat-based spectrographs.  I debut a suite of 4 open-source Python microservices that grapple with the increased volume, variety, velocity-precision, and veracity of the near-IR echelle spectroscopy glut.  These software frameworks include innovations in human-in-the-loop model comparisons and transfer learning for adapting stellar and telluric models to data.  In part two, I report on the direct measurement of starspot emission in heavily spotted T-Tauri stars and underluminous subgiant stars through probabilistic decomposition of IGRINS, K2, TESS, and HPF data.  Quantifying physical properties of starspots mitigates the deleterious "Transit Light Source Effect" in exoplanet transmission spectroscopy.  In part three, I critically evaluate precomputed synthetic spectral models of ultracool dwarfs, the closest analogs to directly imaged exoplanets currently amenable to echelle spectroscopy.  Finally, I highlight results from the ongoing HPF Helium exospheres program with a case study of HAT-P-67 b, exploring the prospect of star-planet interaction in this extreme stellar system.

Host:  Ian Czekala

Please email CEHW-SEMINAR-QUESTIONS@lists.psu.edu to register.