EPS Japan 1999,June (in Yoyogi)
Inoue S., Ogawa S.,(Misato Tech. High), Machimura
H., Sugita A., Watanabe M., (Seikei High),Leonid 98 Project (2576 students).
We participated in the Leonid meteor observation network with naked eye
for@senior-high school sutudents on Nov. 18@1998. The aim of observation
was to seek to clarify the dust-tube structure which produced by the parent
comet 55p/Tempel-Tuttle. The network comprised the 268 observation teams
consisting of about 2600 senior-high school students. Each observation
point was located about several tens of kilometer from the next points,
and were scattered from Hokkaido to Okinawa. In order to research detail
information of the dust-tube structure, the period of meteor counting is
necessary for a 10 minute interval. Without the coastal range of the Japan
Sea, the weather was almost fine, and over 250 groups carried out successful
observation.
As a result of our observation, the maximum hourly rate with correction
of radiation point altitude was about 100 counts/hour. This rate is the
lower limit of predicted flux (Z. Wu, and I.P.Williams, 1996), and means
that the average distance of meteoroids is roughly estimated as about 600
km. With this condition, over the Japanese islands, the apparent difference
of hourly rate and/or peak time of meteor shower was not detected on the
basis of the analyses using the selected data. The small peak time of shower
(around 4h00m on Nov. 18 JST) was consistent with the predicted time when
the earth would cross 55p/Tempel-Tuttle orbital plane. Consequently, the
inhomogeneity within a 1000km scale was not clearly observed on the dust-tube
of the comet.