IAU Report on TV Meteor Activity for 1993-1996

The most significant video meteor observational investigation during the past three year period was the extensive two station study by Ueda and Fujiwara (1995) (from Japan) which provides complete orbital data as well as atmospheric trajectory information for 265 meteors (326 meteors were partially analysed) down to +7 absolute magnitude. In addition to a large number of sporadic meteors, at least a few members of 13 meteor showers (5 apparently not previously detected) were observed, with significant representation of the eta Aquarid, Leonid, and Geminid showers. The paper compares the observed radiant distribution with predictions from cometary and near earth asteroids, although one must be wary of observational selection effects (single latitude of observations, concentration of data from the fall months). Another detailed two station study was that by de Lignie and Jobse (1996) who provided trajectory and orbital information for 29 Quadrantid and 20 sporadic meteors. Suzuki et al. (1994a) made a convincing case (using orbital determinations from double station television observations) for detection of a new shower active in mid-January and with a radiant near Coma Berenices. Suzuki et al. (1994b) also published data from a multi-station study of the 1993 Perseid data, providing orbital elements for 34 Perseids. Suzuki et al. (1993) provided a study of the eta Aquarid shower at television magnitudes.

Single station observation techniques were employed by a number of authors. Hawkes and Fleming (1995) determined a rate profile for the Perseid shower at television magnitudes. Molau (1995a) reported on single station observations for the Quadrantid and Perseid showers, providing detailed radiant information, as well as an investigation of time clustering in the Perseid data.

Television observations continued to play a role in defining the physical structure and chemical composition of meteoroids. Shadbolt and Hawkes (1995) reported on the apparent absence of wake in faint sporadic meteors, indicative of either a very narrow grain size spectrum or an absence of fragmentation. Borovicka and Bocek (1995) have used television techniques in the study of meteor spectra.

Molau (1995b) compared video based meteor magnitudes with those estimated by visual observers, finding that on average visual observers underestimate the brightness of meteors by about one-half magnitude, with little velocity or brightness correlation. Fujiwara et al. (1995) employed intensified video methods in conjunction with a middle and upper atmospheric radar system, providing a relation between radar echo duration and meteor magnitude. Meisel et al. (1995) combined video with a variety of other observational techniques in the study of a -10 magnitude fireball. Several papers (Brown et al., 1994; Beech et al., 1995; Ceplecha et al., 1996) reported on analysis of the spectacular Peekskill meteorite fireball, which was recorded by both high resolution still camera and at least 15 video cameras. This provides the most detailed atmospheric fragmentation record ever of a meter- sized meteoroid.

The MOVIE software developed by Sirko Molau in Germany for the analysis of video meteor data is documented in Molau (1995c). A proposed automated television detection system is described by Gural (1995).

Sirko Molau has provided an important service to the professional and amateur television meteor community by setting up a comprehensive WWW page with background information, sample images, analysis techniques, reference lists, and the complete text of a number of papers. The URL is: http://www.imo.net/video

• Beech M., Brown P., Hawkes R.L., Ceplecha Z., Mossman K., Wetherill G., 1995
  Earth, Moon, and Planets 68, 189-197.
• Borovicka J., Bocek J., 1995
  Earth, Moon, and Planets 71, 237-244.
• Brown P., Ceplecha Z., Hawkes R.L., Wetherill G., Beech M., Mossman K., 1994
  Nature 367, 624-626.
• Ceplecha Z., Brown P., Hawkes R.L., Wetherill G., Beech M., Mossman K., 1995
  Earth, Moon, and Planets 72, 395-404.
• de Lignie M, Jobse K. 1996
  WGN 24, 20-26.
• Fujiwara Y., Ueda M., Nakamura T., Tsutsumi M., 1995
  Earth, Moon and Planets 68, 277-282.
• Gural P., 1995
  WGN 23, 228-235.
• Hawkes R.L., Fleming D.E.B., 1995
  Earth, Moon and Planets 68, 303-310
• Meisel D.D., Getman V.S., Mathews J.D., Jacobs S.C., Roper R.G., 1995
  Icarus 116, 227-254.
• Molau S., 1995a
  WGN 23, 217-224.
• Molau S., 1995b
  WGN 23, 225-228.
• Molau S., 1995c
  Proc. of the IMC 1994, 51-61.
• Shadbolt L., Hawkes R.L., 1995
  Earth, Moon and Planets 68, 493-502.
• Suzuki K., Akebo T., Suzuki S., Yoshida T., 1993
  WGN 21, 214-215.
• Suzuki K., Akebo T., Suzuki S., Yoshida T., 1994a
  WGN 22, 50-51.
• Suzuki K., Yoshida T., Suzuki K., Akebo T., 1994b
  WGN 22, 137-139.