Starspot Imaging with the CHARA Array

We present the first results of a starspot interferometric imaging program targeting the chromospherically active giant Lambda Andromedae. Our images are constructed using a new starspot model that incorporates a power limb darkening law and starspot foreshortening. The model solutions are determined through χ minimization of observed squared visibilities, triple amplitudes and closure phase. Model solutions are compared with images generated from interferometric image reconstruction. We present Monte Carlo tests on the confidence of this model to recover stellar size, starspot covering factor, starspot position and temperature ratio between the starspot and surrounding photosphere. The project’s results have implications on observational design and feasibility to image small scale surface structures.