Electronic Telegram No. 944
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


ETA AQUARIIDS 2007
     M. Sato and J. Watanabe, National Astronomical Observatory of
Japan, report that their calculations regarding the dust trails of
comet 1P/Halley, stimulated by the unexpected outburst of the Orionids
in 2006, indicate that a certain dust trail ejected from 1P/Halley in
-835 will encounter the earth this year on the opposite side of its
orbit, leading to an enhanced level of activity of eta Aquariid meteors
on May 6.6 UT.  Other possible trails were studied, but only that of
-835 appears to be in line with the earth's orbit this year.  This
particular trail is so old that its shape is very complex due to the
accumulated effect of the perturbations, which are mainly from the
Jovian effect or resonance; this may result in longer activity, along
with a lower level of activity.  Details are given at
http://fas.kaicho.net/tenshow/meteor/1p2007/EAqr2007.htm.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2007 CBAT
2007 April 25                    (CBET 944)               Daniel W. E. Green