We report a tentative detection of spin correlations in the Tully catalogue
of nearby galaxies. We define a simple but nontrivial spin correlation
function, and find an analytic estimate of it in the frame of the linear
perturbation theory. Then, we present the observed spin correlation signal from
the Tully galaxies with error bars. The three dimensional spin correlation
turns out to be significant at the 97% confidence level, detected out to a few
h−1 Mpc. This observed correlation is consistent with the theoretical
prediction based on the gravitational instability picture of galaxy formation.
An analysis of systematic errors is also presented. The observed strength of
correlation may be sufficient to significantly affect blank field of weak
lensing searches.Comment: Accepted by the ApJ Letters, revised Physical Analysis, LaTex file,
10 pages, 1 ps figur