Discovery of optical flickering from the symbiotic star EF Aquilae

Abstract

We report optical charge‐coupled device (CCD) photometry of the recently identified symbiotic star EF Aquilae (EF Aql). Our observations in the Johnson V and B bands clearly show the presence of stochastic light variations with an amplitude of about 0.2 mag on a time scale of minutes. The observations point toward a white dwarf (WD) as the hot component in the system. It is the 11th object among more than 200 symbiotic stars known with detected optical flickering. Estimates of the mass accretion rate onto the WD and the mass loss rate in the wind of the Mira secondary star lead to the conclusion that less than 1% of the wind is captured by the WD. Eight further candidates for the detection of flickering in similar systems are suggested.