  We place direct upper limits on the amplitude of gravitational waves from 28
isolated radio pulsars by a coherent multi-detector analysis of the data
collected during the second science run of the LIGO interferometric detectors.
These are the first direct upper limits for 26 of the 28 pulsars. We use
coordinated radio observations for the first time to build radio-guided phase
templates for the expected gravitational wave signals. The unprecedented
sensitivity of the detectors allow us to set strain upper limits as low as a
few times $10^{-24}$. These strain limits translate into limits on the
equatorial ellipticities of the pulsars, which are smaller than $10^{-5}$ for
the four closest pulsars.
