We observed the 1994 , 1996 and 2001 outbursts of HO Del .
From the detection of secure superhumps , HO Del is confirmed to be an SU UMa-type dwarf nova with a superhump period of 0.06453 ( 6 ) d. Based on the recent observations and the past records , the outbursts of HO Del are found to be relatively rare , with the shortest intervals of superoutbursts being \sim 740 d. Among SU UMa-type dwarf novae with similar outburst intervals , the outburst amplitude ( \sim 5.0 mag ) is unusually small .
HO Del showed a rather rapid decay of the superhump amplitudes , and no regrowth of the amplitudes during the later stage , in contrast to the commonly observed behavior in SU UMa-type dwarf novae with long outburst intervals .
We positively identified HO Del with a ROSAT X-ray source , and obtained a relatively large X-ray luminosity of 10 ^ { 31.1 \pm 0.2 } erg s ^ { -1 } .
We also performed a literature survey of SU UMa-type dwarf novae , and presented a new set of basic statistics .
The SU UMa-type dwarf novae with a brightening trend or with a regrowth of superhumps near the termination of a superoutburst are found to be rather tightly confined in a small region on the ( superhump period–supercycle length ) plane .
These features may provide a better observational distinction for the previously claimed subgroup of dwarf novae ( Tremendous Outburst Amplitude Dwarf Novae ) .