ProAm

A procedure to obtain the persistent train population index, tau, is proposed. This is based on the assumption that train duration can be described by a population index, like meteor brightness. With this method we obtain tau for the fireballs from Perseids (tau =0.919+-0.400 in the interval [1 s, 45 s]), Leonids (tau = 0.807+-0.273 in the interval [1 s, 10 s] and tau = 0.993+-0.135 in the interval [13 s, 600 s]), Geminids (tau = 0.820+-0.670) and the sporadic background (tau = 0.600+-0.180) from the SOMYCE database. These values are compared with those obtained for faint meteors to +6 magnitude. A global fit with the FIDAC Database gives tau = 0.899+-0.157 in the interval [1 s, 20 s] and tau = 0.997+-0.230 in the interval [21 s, 900 s]. Finally, a relationship between the visual magnitude and tau is sought in the interval [-3 magnitude, -8 magnitude] with a fit tau= cm_{ v}+ m_{v0}=-0.018 m_{v} + 0.808. Variations of tau are discussed.

The Sociedad de Observadores de Meteoros y Cometas de Espana) (SOMYCE) has produced a DVD set with many useful astronomical observations. The data are outlined and made available.

Naked eye meteor records from Spain are used for an analysis of 3240 fireballs reported by members of the Sociedad de Observadores de Meteoros Y Cometas de España (SOMYCE) and by casual eye-witnesses from 1982 to 2000. This analysis concerns various areas, such as statistical studies of the colours and the frequency of fireballs in annual meteor showers. Annual and diurnal variations are also discussed. We describe the population index r for magnitudes brighter than m=-2 for ORI, VIR, AQU, TAU, CAP, QUA, GEM, LYR, LEO, KCG, PER and sporadic fireballs. The typical population index is always in the range ≃ 1.2 to 1.9, except for Perseids and Geminids. An investigation of visual fireballs radiants was attempted with the Radiant software. The sample of fireballs (282 fireballs with the path reported) only shows evidence for the Perseids and Leonids.

The properties of Leonids and its persistent trains produced from fireballs are investigated with visual records carried out by SOMYCE members from 2616 fireballs brighter than visual magnitude -2 which left 663 persistent trails of known duration. The "population index", tau, for the train distribution in 1998 was tau=0.838+-0.053 for the interval [=<0.5 s, 8 s], tau=0.979+-0.010 from the interval [10 s, 30 s], and tau=0.995+-0.049 for the interval [35 s, 600 s]. In 1999, tau was lower: tau=0.468+-0.166 for the interval [0.5 s, 7 s], while in the 2000 data, similar values as from the 1998 observations are found with tau=0.976+-0.255 for [=<0.5 s, 150 s]. These values are greater than the usual ones of sporadic fireballs with 0.67+-0.01.

We report our observations of meteors made with an image intensifier placed on Maspalomas (Gran Canaria, Spain). From 2000 September to March our system has detected 2321 meteors, of which 1485 were sporadics and 836 were from various active radiants.