  We use the fourth data release of the Sloan Digital Sky Survey to investigate
the orientations of 4289 satellite galaxies with respect to their hosts. The
orientation of the satellites is inconsistent with a random distribution at the
99.94% confidence level, and the satellites show a preference for elongation in
the direction of their hosts. Further, on scales < 50 kpc the major axes of the
host galaxies and their satellites are preferentially aligned. Phrased in the
terminology of weak lensing, the images of the satellites have a mean shear of
gamma_T = -0.045 +/- 0.010, averaged over scales 10 kpc < r < 50 kpc. In a
galaxy-galaxy lensing study where lenses and sources are separated solely on
the basis of apparent magnitude, we estimate that on scales < 250 kpc satellite
galaxies acount for between 10% and 15% of the objects that are identified as
sources. In such studies, elongation of the satellites will cause a reduction
of the galaxy-galaxy lensing shear by of order 25% to 40%. Hence, the
elongation of satellite galaxies in the direction of their hosts is a
potentially important effect for precision studies of galaxy-galaxy lensing and
argues strongly in favor favor of the use of accurate photometric redshifts in
order to identify lenses and sources in future studies.
