Dynamical Surface Imaging of lambda Andromedae

Abstract

We present temperature maps of RS CVn star lambda Andromedae, reconstructed from interferometric data acquired in 2010 and 2011 by the MIRC instrument at the Center for High Angular Resolution Astronomy Array. To constrain the stellar parameters required for this imaging task, we first modeled the star using our GPU-accelerated code SIMTOI. The stellar surface was then imaged using our open source interferometric imaging code ROTIR, in the process further refining the estimation of stellar parameters. We report that the measured angular diameter is 2.742 +/- 0.010 mas with a limb-darkening coefficient of 0.231 +/- 0.024. While our images are consistent with those of prior works, we provide updated physical parameters for lambda Andromedae (R_star = 7.78 +/- 0.05 R_odot, M_star = 1.24 +/- 0.72 M_odot, log L/L_odot = 1.46 +/- 0.04).

18 pages, 10 figures, accepted in ApJ

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