RAT J1953+1859: a dwarf nova discovered through high amplitude QPOs in quiescence

TL;DR

The paper reports the discovery of a dwarf nova, RAT J1953+1859, identified through high amplitude quasi-periodic oscillations during quiescence, highlighting a new method for detecting such systems.

Contribution

It is the first dwarf nova discovered via high amplitude QPOs in quiescence, demonstrating the potential of high-cadence surveys for finding cataclysmic variables.

Findings

Discovered a dwarf nova with ~90 min orbital period.

Detected high amplitude QPOs during quiescence.

Suggests high-cadence surveys can find short-period variables.

Abstract

We report the discovery of an accreting binary, RAT J1953+1859, made during the RApid Temporal Survey (RATS) on the Isaac Newton Telescope. It showed high amplitude (0.3 mag) quasi-periodic oscillations on a timescale of ~20 mins. Further observations made using the Nordic Optical Telescope showed it to be ~4 mag brighter than in the discovery images. These photometric observations, together with radial velocity data taken using the William Herschel Telescope, point to an orbital period of ~90 mins. These data suggest that RAT J1953+1859 is a dwarf novae of the SU UMa type. What makes RAT J1953+1859 unusual is that it is the first such system to be discovered as a result of high amplitude QPOs during quiescence. This suggests that high-cadence wide-field surveys could be another means to discover cataclysmic variables as a result of their short period variability.