Abstract
A total of 18 image intensified CCD detectors were deployed at 6 locations (two in Negev Desert, Israel, and one in each of the Canary Islands, Long Key in Florida, Haleakala in Hawaii, and the Kwajalein Atoll) to provide a real-time reporting system, as well as data for subsequent detailed analysis, for the 1999 Leonid shower. Fields of view ranged from 9 to 34 degrees, with apparent limiting stellar magnitudes from about +7 to +9. In addition, a dual frequency (29.850 and 38.15 MHz) automated meteor radar with directional determination capability was located in the Canadian Arctic at Alert, Nunavut and provided continuous monitoring of the shower from a location where the radiant was constantly above the horizon. Both the radar and electro-optical systems successfully recorded the activity of the shower in real time, and typical real-time activity plots are presented. Post-event analysis has concentrated on the Israel electro-optical wide field cameras and the time interval centered around the peak of the storm. About 2700 meteors have been digitized, with 680 measured for this analysis. Of these 371 were well enough determined to permit a single-station technique to yield approximate heights. Light curves and photometric masses were computed for these 371 Leonids which form the basis of the preliminary results reported in this paper. These cameras recorded Leonid meteors with peak luminosity in the magnitude range −3 to +5, corresponding to the photometric mass range 10−4 to 10−7 kg. A regression plot of photometric mass with magnitude did not indicate any change in light curve shape over the interval studied here. The peak flux as determined by the electro-optical observations was 1.6 ± 0.1 Leonid meteors of magnitude +6.5 or brighter falling on a one square kilometer area (oriented perpendicular to the Leonid radiant) per hour. This peak flux occurred at approximately 2:07 ±: 06 UT on Nov 18 1999, corresponding to solar longitudeλo= 235.248 (epoch 2000.0). The radar results were consistent with this maximum flux rate and time. There was not a strong change in mass distribution over the few hours around maximum, although there is some indication that the peak interval was stronger in fainter meteors. Height histograms are provided for beginning, maximum luminosity and ending heights. It was found that maximum luminosity and ending heights were completely independent of mass, consistent with a dustball model in which the meteoroids are fragmented into constituent grains prior to ablation of the grains. However, the beginning height increases sharply (9.1 km per decade of photometric mass change) with increasing mass. This is possibly indicative of a volatile component which ablates early in the atmospheric trajectory.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Arlt, R.: 1999, WGN: Journal of the IMO 27, 286–295.
Beech, M.: 1984, MNRAS 211, 617–620.
Beech, M., Brown, P., and Jones, J.: 1995, Q. J. R. astr. Soc. 36, 127–152. Beech, M., Brown, P., Jones, J., and Webster, A.R.: 1997, Adv. Space Res. 20, 1509–1512.
Betlem, H., Jenniskens, P., van Leven, J., ter Kuile, C., Johannink, C., Zha.o, H., Lei
C., Li, G., Zhu, J., Evans, S., and Spumy, P.: 1999, Meteoritics Planet. Sci., 34, 979–986.
Brown, P. and Jones, J.: 1995, Earth, Moon and Planets 68, 223–245.
Borovicka, J., Stork, R., and Bocek, J.: 1999, Meteoritics Planet. Sci. 34, 987–994.
Campbell, M.D.: 1998, Light Curves of Faint Meteors: Implications for Physical Structure (B.Sc. Honours Thesis, Mount Allison University, Sackville, NB, Canada.
Campbell, M.D., Hawkes, R.L., and Babcock, D.D.: 1999, in V. Porubcan and W.J. Baggaley (eds.), Meteoroids 1998, Astron. Institute, Slovak Academy of Sciences, Bratislava, p. 363–366.
Campbell, M.D., Brown, P.G., LeBlanc, A.G., Hawkes, R.L., Jones, J., Worden, S.P., and Correll, R.R.: 2000, Meteoritics Planet. Sci.,submitted.
Cevolani, G. and Foschini, L.: 1998, Planet. Space Sci. 46, 1597–1604.
Duffy, A.G., Hawkes, R.L., and Jones, J.: 1987, MNRAS 228, 55–75.
Elford, W., Steel, D., and Taylor, A.: 1997, Advances in Space Research, 20, 1501–1504.
Fleming, D.E.B., Hawkes, R.L., and Jones, J.: 1993, in J. Stohl and I.P. Williams (eds.), Meteoroids and Their Parent Bodies,261–264.
Fujiwara, V., Ueda, M., Shiba, Y., Sugimoto, M., Kinoshita, M., Shimoda, C., and Nakamura, T.: 1998,. Geophys. Res. Lett. 25, 285–288.
Hawkes, R.L. and Jones, J.: 1975, MNRAS 173, 339–356.
Hawkes, R.L. and Jones, J.: 1984, Bull. Astr. Inst. Czechosl. 35, 46–64.
Hawkes, R.L., Mason, K.I., Fleming, D.E.B., and Stultz, C.T.:1993, in D. Ocenas and D., Zimnikoval (eds)., International Meteor Conference 1992, International Meteor Organization, Antwerp, 28–43.
Hawkes, R.L., Babcock, D.D., and Campbell, M.D.: 1998, Analysis Procedures and Final Electro-Optical Results,31 July 1998 CRESTech Contract Report, 58 pgs.
Marsden, B.G.: 1982, Sky & Telescope 64, 284.
McKinley, D.W.R.: 1961, Meteor Science and Engineering (New York: McGraw-Hill). Murray, I.S., Hawkes, R.L., and Jenniskens, P.: 1999, Meteoritics Planet. Sci., 34, 949–958.
Sarma, T. and Jones, J.: 1985, Bull. Astr. Inst. Czechosl. 36, 9–24.
Steel, D.:1998, Astron. Geophys 39, 24–26.
Treu, M., Worden, S.P., Bedard, M.G., and Bartlett, R.K.: 2000, Earth, Moon and Planets 83, 27–38.
Verniani, F.: 1965, Smithson. Contr. Astrophys. 9, 141–172.
von Zahn, U., Gerding, M., Hoffner, J., McNeil, W.J., and Murad, E.: 1999, Meteoritics Planet. Sci., 34, 1017–1027.
Wray, J.D.: 1967, The Computation of Orbits of Doubly Photographed Meteors (Univ. New Mexico Press, Albuquerque, U.S.A.).
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2000 Springer Science+Business Media Dordrecht
About this chapter
Cite this chapter
Brown, P. et al. (2000). Global Ground-Based Electro-Optical and Radar Observations of the 1999 Leonid Shower: First Results. In: Jenniskens, P., Rietmeijer, F., Brosch, N., Fonda, M. (eds) Leonid Storm Research. Springer, Dordrecht. https://doi.org/10.1007/978-94-017-2071-7_13
Download citation
DOI: https://doi.org/10.1007/978-94-017-2071-7_13
Publisher Name: Springer, Dordrecht
Print ISBN: 978-90-481-5624-5
Online ISBN: 978-94-017-2071-7
eBook Packages: Springer Book Archive