We present two series of MOST ( Microvariability & Oscillations of STars ) space-based photometry , covering nearly continuously 10 days in 2004 and 30 days in 2007 , of selected variable stars in the upper Main Sequence of the old open cluster M67 .
New high-precision light curves were obtained for the blue-straggler binary/triple systems AH Cnc , ES Cnc and EV Cnc .
The precision and phase coverage of ES Cnc and EV Cnc is by far superior to any previous observations .
The light curve of ES Cnc is modelled in detail , assuming two dark photospheric spots and Roche geometry .
An analysis of the light curve of AH Cnc indicates a low mass ratio ( q \sim 0.13 ) and a high inclination angle for this system .
Two new long-period eclipsing binaries , GSC 814–323 and HD 75638 ( non-members of M67 ) were discovered .
We also present ground-based DDO spectroscopy of ES Cnc and of the newly found eclipsing binaries .
Especially interesting is HD 75638 , a member of a visual binary , which must itself be a triple or a higher-multiplicity system .
New light curves of two \delta Scuti pulsators , EX Cnc and EW Cnc , have been analyzed leading to detection of 26 and 8 pulsation frequencies of high temporal stability .