BM UMa: a middle shallow contact binary at pre-transition stage of evolution from W-type to A-type

T. Sarotsakulchai, B. Soonthornthum, S. Poshyachinda +3

In this study, all unpublished time series photometric data of BM UMa ($q\sim$ 2.0, P = 0.2712\,d) from available archives were re-investigated together with new data taken from t…