Posted By on Feb 8, 2017 |

We investigate the transmission spectrum produced by the combination of the exoplanet’s atmosphere and the stellar photosphere. In this simple case, the stellar photosphere is comprised of two components with different spectra: a primary component that includes the transit chord and another unocculted component. We find that unocculted stellar faculae covering 3.2% of the stellar disk are the best explanation for the optical spectrum we observe. Credit: B. Rackham