Kepler/K2 and IGRINS constrain starspot filling factors and temperatures.

484347ce845b7236c4791348e0eed9ba?s=47 gully
January 09, 2019

Kepler/K2 and IGRINS constrain starspot filling factors and temperatures.

In this contribution I highlight how large starspot coverage fractions alter the interpretation of existing data: age biases and spreads in young clusters and spectral-type mismatches in the optical and infrared. I showcase results of probabilistic spectral decomposition using custom extensions to the Starfish inference framework. High spectral resolution, high bandwidth near-infrared spectra from IGRINS are shown to detect the collective emission from large starspots and/or spot groups. I demonstrate these precision measurements on the most conspicuously spotted benchmarks, Weak Line T-Tauri Stars in nearby young star forming clusters. I report their starspot coverage fractions and photospheric temperatures. These measurements indicate large biases in isochrone-derived ages of young stars.



January 09, 2019