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The bright blue straggler NSV 4276 in the old open cluster M67 was found to be an eclipsing binary with an orbital period of 1.d0678. Five primary and one secondary eclipses were detected. The amplitude of variability is 0.m12 both in B and V. The primary eclipse depth is 0.m07. The effect of ellipsoidality of the bright companion is seen. It is supposed that this star overflows its Roche lobe on the way to red giants, and that the system is a semidetached binary.
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Goranskij et al. (1992) studied this question.
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