Modeling the photometric and dynamical behavior of Super-Schmidt meteors in the Earth's atmosphere

Abstract

Abstract. Faint meteors observed with Super-Schmidt cameras are re-examined in order to assess whether their dynamical and photometric behavior can be described by means of the single body theory. Velocities, decelerations and magnitudes are fitted simultaneously to synthetic curves resulting from integration of the appropriate set of differential equations. The parameters determined by this procedure are the ablation coefficient, the shape-density coefficient and the preatmospheric mass of each individual meteoroid. It turns out that 73% of the meteors analyzed here (with magnitudes in the range from +2.5 to −5) are reasonably well described by this theory, suggesting that they did not undergo significant fragmentation during their atmospheric flight. Nevertheless, we identify some systematic differences between observed and theoretical light curves of meteors for which the fit is good. Meteoroid bulk densities are estimated from the retrieved shape-density coefficients. The distributions of individual values are broad, indicating that objects of different densities coexist within the same meteoroid population. The average density is found to be 2400, 1400, and 400 kg m −3 for A-type, B-type and C-type meteoroids, respectively. These results do not confirm the large values determined from quasicontinuous fragmentation models.

Properties of meteoroids from different classes of parent bodies

“…Such task is very difficult and the results are model dependent. There is, nevertheless, an agreement that Geminids contain the meteoroids with highest density of all showers (Babadzhanov 2002;Bellot Rubio et al 2002). Other meteoroids with relatively high density are δ-Aquariids and Quadrantids (Babadzhanov 2002).…”

Bulk density of small meteoroids

“…He also divided group C into three subgroups based on orbital elements, but due to our small number statistics, we treat these as one. Equation (5) was developed and first applied to meteors photographed by Super-Schmidt cameras (see Ceplecha 1967Ceplecha , 1988Bellot Rubio et al 2002). For the fainter meteors observed by intensified video systems, the parameter K B is calculated in the same way, but an offset of 0.15 is added (see Ceplecha 1988) because the K B criterion is based on meteor beginning heights, which depend on the sensitivity of the camera.…”

“…To account for this, he introduced the concept of progressive fragmentation (meteoroids fragment progressively into smaller pieces during atmospheric flight). Bellot Rubio et al (2002) found that visible forms of fragmentation (wake and terminal blending) can be present in the lightcurves of some faint meteors showing deceleration anomalies.…”

“…He found values ranging from 400 kg m −3 to 7800 kg m −3 . Bellot Rubio et al (2002) pointed out two questionable assumptions (see Kikwaya et al 2009, for details on the discussion) which led Babadzhanov to estimate these high densities, the most important being the fact that Babadzhanov's (2002) method was only based on fitting the lightcurve, neglecting the meteoroid dynamics. Working on the same data, Bellot Rubio et al (2002), using the single body theory which neglects fragmentation entirely, found bulk densities ranging from 400 kg m −3 to 4800 kg m −3 .…”

“…Bellot Rubio et al (2002) pointed out two questionable assumptions (see Kikwaya et al 2009, for details on the discussion) which led Babadzhanov to estimate these high densities, the most important being the fact that Babadzhanov's (2002) method was only based on fitting the lightcurve, neglecting the meteoroid dynamics. Working on the same data, Bellot Rubio et al (2002), using the single body theory which neglects fragmentation entirely, found bulk densities ranging from 400 kg m −3 to 4800 kg m −3 . The complete model of meteoroid ablation must take into account fragmentation and dynamical properties of the meteoroids simultaneously (Borovicka 2005), as described and applied by Borovicka et al (2007), and Kikwaya et al (2009).…”