Searching for flickering variability in several symbiotic stars and related objects: BX Mon, V471 Per, RS Oph, V627 Cas, CI Cam V886 Her, Z And, T CrB, MWC 560, V407 Cyg

TL;DR

This study presents UBVRI photometry of 10 symbiotic stars, revealing rapid flickering, quasi-periodic oscillations, and some constancy, thereby enhancing understanding of variability behaviors in these systems.

Contribution

It provides new observational evidence of flickering and oscillations in multiple symbiotic stars, including the first confirmation of 29-minute oscillations in Z And.

Findings

Detected rapid flickering in MWC 560, RS Oph, V407 Cyg, and T CrB.

Confirmed 29-minute oscillations in Z And.

Identified some stars with no flickering activity.

Abstract

UBVRI photometry observations of 10 symbiotic stars and related objects obtained in the period 2002-2003 are presented. Analysing differential light curves we found rapid light variations with timescales of tens of minutes and significant amplitudes in the well-known flickerers MWC 560, RS Oph, V407 Cyg and T CrB. MWC 560 and V407 Cyg demonstrate quasi periodic oscillations (QPO) with similar amplitudes and timescales. Flickering and unusual flare in V627 Cas as well as some indications of flickering presence in BX Mon are detected. The existence of 29 minutes oscillations in Z And with an amplitude about 0.02 mag in U band is confirmed. Only one symbiotic star, V471 Per, and both non symbiotic, CI Cam and V886 Her seem to be constant on flickering timescales. Nevertheless, small night to night changes in the brightness of V886 Her were observed as well.