Electronic Telegram No. 1019 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) URL http://www.cfa.harvard.edu/iau/cbat.html PERSEID METEORS 2007 P. Jenniskens, SETI Institute, reports that the Perseid meteors from comet 109P/Swift-Tuttle should peak at ZHR = 80 +/- 20 meteors/hr on 2007 Aug. 13d10h UT (Jenniskens 2006, Meteor Showers and Their Parent Comets, Cambridge Univ. Press, p. 397). Jenniskens adds that a possible encounter with a younger filament component is expected around Aug. 13d04h, with a FWHM = 1.0 hr; this younger filament is an accumulation of many trails over a period of time, thought to be dust moving in mean-motion resonances and being mostly responsible for the Perseid outbursts of the 1989-1997 period. Peak activity can not yet be predicted reliably. Also, I. Sato has identified a weak encounter with the 1479 dust trail of comet 109P on Aug. 12d22h55m. E. Lyytinen calculates a peak time at Aug. 13d00h27m, while J. Vaubaillon has the peak at Aug. 12d22h42m and an estimated duration of FWHM = 0.49 hr. Jenniskens estimates a peak rate of only about ZHR = 20 meteors per hour for this dust-trail encounter, which occurs on top of the stronger annual shower activity. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2007 CBAT 2007 August 2 (CBET 1019) Daniel W. E. Green