Analisi in multibanda dello sciame meteorico delle Liridi

The Lyrids meteor stream has a medium activity and its origin is cometary. Their parent body is the comet Thatcher, that passed the last time near Earth in 1861. The stream occurs in the last days of April and the maximum of activity occurs in the days from 21 to 23 April. The Lyrids were studied from 1994 to 2004 using two different techniques: visual and radio observation. The visual data were taken from the internet archive of International Meteor Organization. The analysis’s procedure follows in part the indication of this Organization. The radio data were obtained using the meteor scatter techniques. The data were taken from the Radio Meteor Observation Bullettins. The purpose of this analysis is the definition of main characteristics of the stream. The solar longitude of the maximum of the activity is λ0 = 32.2° ± 0.2° from radio data and λ0 = 32.2° ± 0.1° from visual data. The ZHR during the maximum is 25 ± 3 and medium ZHR is 13 ± 1. The data show the evidence of a complexity in the structure of the spatial distribution of matter and no evidence of periodicities in the activity.