Electronic Telegram No. 5049
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
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Prepared using the Tamkin Foundation Computer Network


ARID METEORS 2021
     Further to CBET 5046, Q.-Z. Ye, University of Maryland; J. Vaubaillon,
IMCCE and Observatoire de Paris; M. Sato, National Astronomical Observatory of
Japan; and M. Maslov, Novosibirsk State University and Novosibirsk State
Technical University, report their updated prediction of the meteoroid-trail
encounter of dust ejected from comet 15P/Finlay during its last perihelion
passage in 2014-2015.  The predicted encounter is between approximately 2021
Oct. 6d22h00m-7d01h00m UT (note this correction to the text in CBET 5046),
with the radiant located near R.A. = 256 deg, Decl. = -48 deg (equinox
J2000.0) with a geocentric velocity of 10.7 km/s.  Comet 15P experienced two
outbursts in 2014-2015 (Ye et al. 2015, Ap.J. 814, 79; Ishigoru et al. 2016,
A.J. 152, 169) from which the ejecta is expected to come into the path of the
earth -- hence, significant meteor activity is possible, with a small chance
of reaching storm level.  The Zenith Hourly Rates calculated by different
forecasters are 5-50 (Maslov) and 178 meteors/hr (Vaubaillon 2020, JIMO 48,
29) without correcting for the heightened cometary activity, and 30-100
(Sato) and 600-1100 meteors/hr (Ye) with heightened activity accounted for.
Based on the comet photometry, the meteor activity could increase by up to a
factor of 10-20 due to the cometary outburst.  Observations are strongly
encouraged.  The most favorable locations to observe this outburst are South
America and Antarctica.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2021 CBAT
2021 October 4                   (CBET 5049)              Daniel W. E. Green