Analysis of the MOST light curve of the heavily spotted K2IV component of the single-line spectroscopic binary II Pegasi

Abstract

Continuous photometric observations of the visible component of the single-line, K2IV spectroscopic binary II Peg carried out by the MOST satellite during 31 consecutive days in 2008 have been analyzed. On top of spot-induced brightness modulation, eleven flares were detected of three distinct types characterized by different values of rise, decay and duration times. The flares showed a preference for occurrence at rotation phases when the most spotted hemisphere is directed to the observer, confirming previous similar reports. An attempt to detect a grazing primary minimum caused by the secondary component transiting in front of the visible star gave a negative result. The brightness variability caused by spots has been interpreted within a cold spot model. An assumption of differential rotation of the primary component gave a better fit to the light curve than a solid-body rotation model.

arXiv commentAccepteed to MNRAS

References in corpus (3)

• An Upper Limit on the Albedo of HD 209458b: Direct Imaging Photometry with the MOST Satellite
• The Differential Rotation of Kappa1 Ceti as Observed by MOST
• Spots, plages, and flares on lambda Andromedae and II Pegasi

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