QY Per updated superhump period The application of PDM to Gianluca Masi's dataset (cf. vsnet-alert 3877, 3883) has yield the most likely superhump period of 0.0828 day. The combination with the Kyoto data on Dec. 29 (moderately affected by the extinction and passing clouds) tends to give a slightly longer period (0.0825 - 0.0840 day depending on the data segment used). The Kyoto team is currently taking a long run under excellent sky condition. Although the present analysis firmly support the long-period nature of QY Per, we hope we can provide a far better-defined superhump period after finishing the analysis of the present run, and the scheduled successive run by Masi. Best regards, Taichi Kato, Makoto Uemura, Gianluca Masi