We present time-resolved CCD photometry of LL And during its 1993 outburst .
The observation revealed the presence of superhumps with a period of 0.05697 ( 3 ) d. This period is one of the smallest among the hydrogen-rich dwarf novae .
Although LL And has been proposed to be a WZ Sge-type dwarf nova based on its low outburst frequency , our new analysis indicates that the outburst amplitude ( \sim 5 mag ) and outburst duration ( 9 \pm 2 d ) are much smaller and shorter than in typical WZ Sge-type dwarf novae .
We suspect that the unusual outburst properties of LL And might be explained by assuming a “ leaky disk ” in quiescence , which was originally proposed to explain the prototypical WZ Sge-type outbursts .
By combination with the recent suggestion of the orbital period , the fractional superhump excess is found to be 3.5 ( 1 ) % , which is unusually large for this short-period system .
LL And may be an object filling the gap in the evolutionary track , which has recently been proposed to explain the unusual ultracompact binaries with an evolved mass donor .