Magnetic activity of KIC 2852961–Revisiting the superflaring red giant in the Kepler field

Abstract

Superflares observed on giant stars can reach energies many orders of magnitude higher than the most powerful solar flares, raising fundamental questions about their physical origin and whether they can be explained by scaled-up versions of solar-type magnetic dynamo processes. In this work, we revisit our previous target, the superflaring red giant star KIC 2852961, to reexamine its flare activity and refine our previous interpretation in light of new observations. We refine the absolute parameters based on the new parallax from Gaia DR3 and show that our red giant star is actually the primary component of a close binary system, the other member of which is a faint red dwarf, which we have only speculated about so far. We consider the possible effects of binarity, since in such close RS CVn systems there is good reason to assume that tidal effects modulate the magnetic activity of the primary star, and may even affect the occurrence of flares along the orbital phase.