Observations of the Leonid Meteoroid Stream by a Multistation FS Radio System

Results of joint campaigns of the Leonid meteoroid stream performed throughout the 1995–1999 years by the BLM (Bologna-Lecce-Modra) forward scatter (FS) radar, are shown and compared with visual observations. In 1998 and 1999 at both the stations of Lecce and Modra, the total reflection time is shown to give a better indication of the Leonid activity. For the two years the trends of the reflection time and of the overdense echoes (T > 8 sec duration) exhibit multiple peaks just at the maximum of the shower activity. In 1999, strong evidence of a short and extremely intense activity at the nodal longitude of the parent comet (November 18, 02h UT), is deduced from the radio data. The Leonid display is shown to follow a Gaussian activity profile and the particle density/stream width relationship is found to match observations of IRAS dust trails of comparable short-period comets. The mass distribution exponent shows a representation of an extended component of larger particles (brighter Leonids) in 1996 and especially in 1998. Average mass and population indices of radio and visual data show a similar trend in the 1995–1999 period.