  Differential time series photometry has been derived for 46422 main-sequence
stars in the core of 47 Tucanae. The observations consisted of near-continuous
160-s exposures alternating between the F555W and F814W filters for 8.3 days in
1999 July with WFPC2 on the Hubble Space Telescope. Using Fourier and other
search methods, eleven detached eclipsing binaries and fifteen W UMa stars have
been discovered, plus an additional ten contact or near-contact non-eclipsing
systems. After correction for non-uniform area coverage of the survey, the
observed frequencies of detached eclipsing binaries and W UMa's within 90
arcseconds of the cluster center are 0.022% and 0.031% respectively. The
observed detached eclipsing binary frequency, the assumptions of a flat binary
distribution with log period and that the eclipsing binaries with periods
longer than about 4 days have essentially their primordial periods, imply an
overall binary frequency of 13 +/- 6 %. The observed W UMa frequency and the
additional assumptions that W UMa's have been brought to contact according to
tidal circularization and angular momentum loss theory and that the contact
binary lifetime is 10^{9} years, imply an overall binary frequency of 14 +/- 4
%. An additional 71 variables with periods from 0.4 - 10 days have been found
which are likely to be BY Draconis stars in binary systems. The radial
distribution of these stars is the same as that of the eclipsing binaries and W
UMa stars and is more centrally concentrated than average stars, but less so
than the blue straggler stars. A distinct subset of six of these stars fall in
an unexpected domain of the CMD, comprising what we propose to call red
stragglers.
