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KS UMa: superhumps update Dear Colleagues, We have received new data from Tonny Vanmunster (two nights, as already reported by Tonny) and the Nyrola team. New data by the Kyoto team and Torii-san (RIKEN) have been also added. The resultant mean superhump period is 0.07026(2) d. This period (most likely progressively updated) is now the best determined superhump period of KS UMa. We have now detected a significant period change. The rate of change dot(P)/P is around -3*10(^4). Since the baseline is still short, we must wait for another days to confirm this trend. If confirmed, this negative period derivative is one of the most pronounced among moderate-period SU UMa-type dwarf novae. This might partly resolve the inconsistency of the superhumps periods determined on different occasions. Except for UV Gem and recently discovered objects such as V877 Ara and KK Tel, there is a tendency that the dot(P)/P makes a minimum around P=0.075 d (Kato et al. (2002) PASJ 54, 1017). KS UMa would be another, but possibly more striking, object following this trend. Further observations to completely follow the superhump evolution are encouraged. Regards, Taichi Kato VSNET Collaboration team
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