The 1992 outburst of the SU ursae majoris-type dwarf nova HV virginis

The results of 14 nights of photometric monitoring the cataclysmic variable HV Vir, following its outburst in 1992 April, are presented. The star displays all major features of the superhump phenomenon which characterizes the SU UMa class of dwarf novae. A fairly chaotic "early superhump variability" was observed on days 2 and 3 after maximum light, although the occurrence of a superhump structure with a period of 85^m is already indicated on day 2. The mature superhump structure appeared on day 3.5 and persisted for ∼20 days, i.e., during the major outburst phases. Its initial period of 84^m48^s decreased in the course of the outburst by 45 s. A stable periodicity of 83^m30^s7, which we interpret as the orbital period, characterizes the photometric behavior of the star during final decline from ∼2^m to ∼1^m above minimum. The superhump shows marked amplitude variations which are related to the difference between superhump and orbital phase. Additional outbursts of HV Vir took place in 1929, 1939, 1970, and 1981. We underline the similarities and differences between HV Vir and two other extreme members of the SU UMa group, compare the photometric behavior of HV Vir with published numerical simulations of the superhump phenomenon, and discuss observable features which might help to establish refined models of the superhump phenomenon.