A telescopic search for large Perseid meteoroids

Abstract

A search for metre-sized and larger exo-atmosphere Perseid meteoroids via their surface reflected sunlight has been made with the 1.2-m Elginfield Telescope. A total survey time of 9.66 h was accumulated during the nights of 2002 August 10, 11 and 12. To a limiting apparent magnitude of +17, we made no distinct detection of any large exo-atmosphere Perseid meteoroids. Our telescopic survey results constrain the upper limit to the spatial number density of metre-sized and larger Perseid meteoroids to be less than ∼3 × 10-3 per 109 km3. We have also analysed a data set of possible in-atmosphere Perseid fireball events detected by space-based optical and infrared sensors. Operating at a detection threshold of magnitude -17, the space-based sensors have detected eight possible Perseid fireballs in the 15-d window, centred on the time of shower maximum, over the cumulative time interval from 1978 August to 2000 August. The space-based sensor data yield a spatial number density of ∼7 × 10-8 per 109 km3 for metre-sized and larger Perseid meteoroids.