A possible massive asteroid belt around zeta Leporis

We have used the Keck I telescope to image at 11.7 and 17.9 mum the dust em ission around zeta Leporis, a main-sequence A-type star at 21.5 pc from the Sun with an infrared excess. The excess is at most marginally resolved at 17.9 mum. The dust distance from the star is probably less than or equal to 6 AU, although some dust may extend to 9 AU. The mass of observed dust is s imilar to 10(22) g. Since the lifetime of dust particles is about 10(4) yr because of the Poynting-Robertson effect, we robustly estimate at least 4 x 10(26) g must reside in parent bodies, which may be asteroids if the syste m is in a steady state and has an age of similar to 300 Myr. This mass is a pproximately 200 times that contained within the main asteroid belt in our solar system.