Fragmentation Model Analysis of EN270200 Fireball

Abstract

We present results on the MFM analysis (Meteor fragmentation model recently proposed by Ceplecha and ReVelle, 2005) of EN270200, a type-I fireball of maximum absolute magnitude ???10 from February 27, 2000, 19 h 22 m 57 s UT, based on observational data from four Czech stations of the European Fireball Network equipped with fish-eye cameras. Radiometer record of the light curve with time resolution of 1200 records per second is also available. Two grating spectra point to composition of an ordinary chondrite. Data on height and stellar magnitude were available at 73 individual trajectory points. The standard deviation of our fit was ??28 m for height as function of time and ??0.11 magnitude for the light curve. Ablation coefficient was found to be constant during the entire trajectory (0.004 s2 km???2). The shape-density coefficient varied in a wide range of values (1.65 and 0.12 c.g.s.). We found 17 fragmentation events during the entire photographic light curve, 7 of them larger than 1% of the main body mass. All fragmentation occurred in a form of clusters of tiny fragments. The initial mass resulted as 3.6 ?? 0.2??kg at a height of 80.144??km with velocity of 18.790??km s???1, and the terminal mass was 0.27 ?? 0.02??kg at a height of 31.62??km with velocity of 6.64 ?? 0.12??km s???1. We were able to explain the very short millisecond flare by the MFM model.