Dynamical Surface Imaging of lambda Andromedae

TL;DR

This paper presents high-resolution temperature maps of the star lambda Andromedae using interferometric data, refining stellar parameters and demonstrating the effectiveness of advanced imaging and modeling techniques.

Contribution

It introduces a combined approach using GPU-accelerated modeling and interferometric imaging to improve stellar surface imaging and parameter estimation.

Findings

Measured angular diameter of 2.742 mas with high precision

Updated stellar parameters including radius, mass, and luminosity

Validated imaging results against prior studies

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).