An analysis of photographic observations of the Leonid meteoric shower in 1999

Photographic observations of meteors can provide more information than visual observations. In this paper, two photographs of Leonid meteoric shower taken on 1999 November 19 have been analyzed. The maximal angular velocity of meteoroids that cancan show up on films has been evaluated. The elevation of the beginning point, angular distance between the ending point and the radiant, angular velocity and arc length of the meteorʹs path are calculated for the two observed meteors. In addition, the observed short duration of about 0.65 second for the ablation of the meteoroids in the atmosphere means that the path length of ablation is about 40–50 kilometers. Through digitized processing of the photographs, photographic magnitudes of −10.3±0.2 and −4.8 ± 0.2 have been measured for the two Leonid meteors, from which their masses and electric line densities can be derived. The procedure given in this paper could be used for photographic observations of other meteors. We also discuss how to select a camera lens for meteor observations.