A nanoflare explanation for periodic variations in flare stars

Several studies have documented periodic and quasi-periodic signals from the time series of dMe flare stars and other stellar sources. Such periodic signals, observed within quiescent phases (i.e., devoid of larger-scale microflare or flare activity), range in period from 1-1000 seconds and hence have been tentatively linked to ubiquitous p-mode oscillations generated in the convective layers of the star. As such, most interpretations for the observed periodicities have been framed in terms of magneto-hydrodynamic wave behavior. However, we propose that a series of continuous nanoflares, based upon a powerlaw distribution, can provide a similar periodic signal in the associated synthetic time series. Monte Carlo simulations, embodying the nanoflare signals and modeled noise profiles, produces a time series consistent with previous observations of dMe flare star lightcurves. Through an examination of nanoflare decay timescales and differing powerlaw indices, we provide evidence that periodic signals found in stellar time series can be explained by low-energy nanoflares embedded within the noise envelope of a stellar lightcurve. Implications for spatially-resolved solar datasets, including those from SDO/AIA, will also be discussed.