Detection of optical flickering from the symbiotic Mira-type binary star EF Aquilae

TL;DR

This study detected optical flickering in the symbiotic Mira-type binary star EF Aquilae, revealing stochastic light variations that confirm the white dwarf nature of its hot component, marking it as the 11th such star with flickering observed.

Contribution

It provides the first detailed photometric analysis of EF Aquilae's flickering behavior, confirming its white dwarf component and expanding knowledge of symbiotic star variability.

Findings

EF Aquilae exhibits stochastic flickering with about 0.25 mag amplitude on 5-minute timescales.

EF Aquilae is the 11th symbiotic star with detected optical flickering.

No flickering above 0.03 mag was detected in SU Lyncis.

Abstract

We performed photometry with a 1 minute time resolution of the symbiotic stars EF Aquilae, AG Pegasi and SU Lyncis in Johnson B and V band. Our observations of the symbiotic Mira-type star EF Aql demonstrate the presence of stochastic light variations with an amplitude of about 0.25 magnitudes on a time scale of 5 minutes. The observations prove the white dwarf nature of the hot component in the binary system. It is the 11th symbiotic star (among more than 200 symbiotic stars known in our Galaxy) which displays optical flickering. For SU Lyn we do not detect flickering with an amplitude above 0.03 mag in B band. For AG Peg, the amplitude of variability in B and V band is smaller than 0.05 mag and 0.04 mag respectively.