Peculiar Velocity of the Sun and the Cosmic Microwave Background

The sun's peculiar velocity with respect to distant galaxies is roughly estimated from the red-shift data for nearby galaxies to be ∼400 km/sec toward $l_{\mathrm{II}}\sim 335°$, $b_{\mathrm{II}}\sim 7°$. Future observations on the angular distribution of the cosmic microwave background should be able to test this estimate, if the background has a cosmological origin. If the test is successful it would imply that a "local" inertial frame is nonrotating with respect to distant matter to an accuracy of ${10}^{-3\mathrm{}}$ sec of arc per century, which would represent a 5000-fold increase of accuracy.