IMO Circular - Leonids 2002
I M O S h o w e r C i r c u l a rMore articles in IMO
Two strong activity peaks of the Leonid meteor shower were predicted. The times fell between 03:48 to 04:04 UT for the first one, and between 10:23 to 10:47 UT for the second peak,both on November 19, 2002.
A first activity analysis from the reports of 86 observers, who logged 19443 Leonids, is given below. The ZHR refers to a stellar limiting magnitude of +6.5, a radiant elevation of 90 deg, and counts of single observers. A population index of r=2 was applied, although the inspection of data suggests a large abundance of faint meteors, thus a larger r. The ZHRs would increase likewise.
The peak time of the first maximum is 04:10 UT with ZHR=2350. The second peak is found near 10:50 UT or a few minutes earlier with ZHR=2660. Both peaks occurred later than the predictions by about the same time lapse. The predictions of the Leonid stream model of Vaubaillon (WGN 30:5, 2002) are closest to reality according to this first analysis.
Solar longitudes refer to equinox J2000.0, N is the number of observing periods involved in the average ZHR, LEO is the number of Leonid meteors. The error of the ZHR is simply ZHR/sqrt(LEO) here. No special zenith exponent was applied to account for non-geometrical effects in radiant elevation correction.
We are very grateful to the enthusiastic community of meteor observers who have sent in their results, mostly through the online express form. All observers are encouraged to send their FULL DATA including magnitudes and possibly shorter time-bins for the counts within the next week.
V. Krumov, M. Gyssens, R. Arlt
2002 November 22