Electronic Telegram No. 1480
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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PERSEID METEORS 2008
     P. Jenniskens and C. I. Webb, SETI Institute; C. Kitting, California
State University, East Bay; and C. L. Peterson, Cloudbait Observatory,
Guffey, CO, U.S.A., report from video observations that no significant
enhanced activity (ZHR > 20 meteors/hr) was detected at the time of the
anticipated 1479-dust-trail crossing in the period 04h00m-06h30m UT on
Aug. 12 (cf. CBET 1464).  The International Meteor Organization (IMO) has
reported normal peak Perseid rates of ZHR = 80 meteors/hr (predicted ZHR
= 110-120 meteors/hr).  Instead, K. Miskotte, Dutch Meteor Society, first
reported an unexpected outburst of Perseids between 0h and 3h UT on Aug. 13.
From a summary of visual observations gathered by the IMO, Geert Barentsen
(European Space Agency/ESTEC) finds a peak at Aug. 13d01h53m +/- 15m UT
(solar longitude = 140.58 +/- 0.01 deg), a peak rate of ZHR = 75 +/- 10
meteors/hr, and a FWHM = 1.9 +/- 0.2 hr, on top of the annual Perseid
activity.  J. Vaubaillon (California Institute of Technology) has identified
this outburst tentatively with the old 441-A.D. dust trail of comet
109P/Swift-Tuttle, which was calculated to fall just outside of the earth's
orbit with a closest encounter on Aug. 12d23h34m UT.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
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                         (C) Copyright 2008 CBAT
2008 August 26                   (CBET 1480)              Daniel W. E. Green