Abstract We present photometric and spectroscopic studies of a new WZ Sagittae (Sge)-type dwarf nova (DN) KSP-OT-202104a discovered by the Korea Microlensing Telescope Network Supernova Program. The source exhibits outburst amplitudes of ∼8 mag with a duration of ∼28.5 days in the V band. It is a type D DN among WZ Sge types, and we estimate the superhump period to be P sh ≈ 71.7 minutes (=0.04978 days). Its spectrum shows blue continuum as often found in optically thick accretion disks of dwarf novae (DNe) during outbursts with hydrogen absorption lines from H β to H ζ . Since the orbital period in WZ Sge-type DNe is typically very close to the superhump period, we consider that this target would belong to the small sample of DNe below the period minimum and may be evolving toward AM Canum Venaticorum stars. This system therefore adds an example of a short-period dwarf nova with a low mass-transfer rate to the known sample.
Ree et al. (Wed,) studied this question.