THE CLOSE BINARY V757 CEN.

The W UMa system V757 Cen has been observed photoelectrically in the UBV system at Bosque Alegre and at El Leoncito Observatories. Full light curves were constructed from 1135 V, 1104 B, and 1104 U individual observations. An improved ephemeris based on about 12,000 cycles is given. A first classical solution for partial eclipses, determined with complementary spectroscopic data, suggests the system to be a contact W UMa star consisting of a larger component of spectral type G1-G2 and F9-G0 companion.