Electronic Telegram No. 1572
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
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LEONID METEORS 2008
     P. Jenniskens, SETI Institute, reports that M. Maslov (Novosibirsk,
Russia) predicted an encounter with the 16-revolution-old (1466 A.D.) dust
trail of comet 55P/Tempel-Tuttle, expecting an outburst of Leonid meteors
with a peak rate of ZHR = 130 meteors/hr on Nov. 17d00h22m UT (solar longitude
234.900 deg, equinox 2000.0); the theoretical radiant position was calculated
to be located at R.A. = 153.5 deg, Decl. = +22.1 deg.  Also, J. Vaubaillon
(California Institute of Technology) calculated that the trail would be
unusually dense and peak at ZHR > 100 meteors/hr at Nov. 17d01h32m UT (solar
longitude 234.949 deg).  The old age of the trail made these predictions
uncertain.  Despite bright moonlight, visual and video observers now report
that they detected higher-than-usual Leonid rates during this time period.
S. Halatzi (Kiryat Ono, Israel) reported a peak rate of roughly ZHR = 120
meteors/hr around Nov. 17d01h30m UT.  P. Ocana (Madrid, Spain) reports high
video rates from 1h30m UT onward at Perseid levels (ZHR about 70-90
meteors/hr).  K. Miskotte (Ermelo, The Netherlands) deduced ZHR = 50-80
meteors/hr from visual observations in an almost-clear period spanning
0h44m-2h00m UT.  K. Antier (Valensole Plate, France) noticed flurries of
Leonids in the period 1h28m-1h38m UT.  J. M. Trigo-Rodriguez (Spanish Meteor
and Fireball Network) reports -- from video observations -- a peak of ZHR =
60 +/- 5 meteors/hr at solar longitude 234.95 deg, accompanied by bright
fireballs from an apparent radiant at R.A. = 153 deg, Decl. = +21 deg, and a
population index of 1.7 +/- 0.3 (N = 150).  The visual observations
collected by the International Meteor Organization show a peak rate of ZHR =
70 meteors/hr at solar longitude 234.982 +/- 0.006 and a duration of FWHM =
0.10 +/- 0.02 deg in solar longitude.
     R. Arlt and J. Rendtel, International Meteor Organization, report
that several visual observers noticed enhanced activity from the Leonid
meteor shower on Nov. 17, with a likely maximum between 1h00m and 1h30m UT.
Estimates of the equaivalent Zenithal Hourly Rate (ZHR) range are as follows:
70 meteors/hr by K. Miskotte, Ermelo, The Netherlands; 70 by R. Haver, Frasso
Sabino, Italy; about 120 by S. Halatzi in Israel; about 150 by F. Zschage,
Kiel, Germany; and 200 by J. Rendtel, Marquardt, Germany.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2008 CBAT
2008 November 18                 (CBET 1572)              Daniel W. E. Green