The distance to Tycho's supernova remnant (3C 10) – a rediscussion

New H I observations of 3C10 at high velocity-resolution (1 km s−1) have been made with the Westerbork Synthesis Radio Telescope. H I absorption can be identified in the velocity range +8 to –52 km s−1. The resulting lower limit for the distance is 4 kpc; the systematic peculiar motions in the Perseus arm have little effect on this determination. A weaker upper limit of 5 kpc has also been determined by a comparison with 3C 11.1, a nearby extragalactic source.