We present photometric observations of four stars that are optical counterparts of soft X-ray/EUV sources, namely 1ES 0829+15.9,
1ES0920-13.6, 2RE J1 10159+223509 and 1ES 1737+61.2. We have discovered periodic variability in two of the stars, viz., MCC
527 (1ES 0829+15.9; Period = 0
d
.828 ± 0.0047) and HD 81032 (1ES 0920-13.6; Period = ∼ 57.02 ± 0.560 days). HD 95559 (2RE J1 10159+223509) is found to show
a period of 3
d
. HD 160934 (1ES1737+61.2) also shows photometric variability but needs to be monitored further for finding its period. These
stars most likely belong to the class of chromospherically active stars.
Key words Stars - variable, optical photometry, X-rays - source