Dwarf nova-type cataclysmic variable stars are significant radio emitters

TL;DR

This study demonstrates that dwarf nova-type cataclysmic variable stars are common radio emitters during outburst, with variable synchrotron emission observed across multiple objects, expanding understanding of their radio properties.

Contribution

It provides the first extensive radio light curves for five dwarf novae, confirming their status as radio emitters and showing variability independent of optical or orbital parameters.

Findings

Radio emission detected in all five studied dwarf novae.

Radio variability occurs on timescales of minutes to days.

No clear correlation between radio luminosity and other system parameters.

Abstract

We present 8--12\,GHz radio light curves of five dwarf nova (DN) type Cataclysmic Variable stars (CVs) in outburst (RX And, U Gem and Z Cam), or superoutburst (SU UMa and YZ Cnc), increasing the number of radio-detected DN by a factor of two. The observed radio emission was variable on time-scales of minutes to days, and we argue that it is likely to be synchrotron emission. This sample shows no correlation between the radio luminosity and optical luminosity, orbital period, CV class, or outburst type; however higher-cadence observations are necessary to test this, as the measured luminosity is dependent on the timing of the observations in these variable objects. The observations show that the previously detected radio emission from SS Cyg is not unique in type, luminosity (in the plateau phase of the outburst), or variability time-scales. Our results prove that DN, as a class, are radio emitters in outburst.