Electronic Telegram No. 5132
Central Bureau for Astronomical Telegrams
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TAU HERCULID METEORS 2022
     Q.-z. Ye, University of Maryland and Boston University; Q.-z. Shen,
S. Huang, M. Chen, and Q.-p. Zheng, Guangdong Meteor Network, report the
possible detection of a meteor outburst of the tau Herculids originating
from the 1892 dust trail from comet 73P/Schwassmann-Wachmann.  The crossing
of the 1892 trail was predicted to occur around 2022 May 30 at 16h UT
(Wiegert et al. 2005, MNRAS 361, 638) and was expected to produce a separate
meteor outburst in addition to the 1995 dust trail which has since been
widely observed (e.g., Jenniskens 2022, CBET 5126).
     The Guangdong Meteor Network's Chinese stations at Puning, Guangdong
(sensitive to meteors down to magnitude about +3) and at Panyu, Guangdong
(sensitive to meteors down to magnitude about +1) recorded fifty and six
unique single-station meteors, respectively, that can be traced to the
predicted tau Herculid radiant.  Both stations are equipped with cameras of
different configurations covering the entire sky.  The tau Herculid meteors
were detected between 11h59m and 17h59m UT on May 30, with the peak activity
occurring within the period 15h30m-16h00m UT (in which fourteen tau
Herculids were detected in a 30-minute interval).  After correcting for the
field-of-view factor, the limiting magnitude, the zenith distance of the
radiant, the authors estimate that the average Zenith Hourly Rate (ZHR) at
15h-16h UT was about 45 tau Herculid meteors, assuming a population index of
2.5.  This is in line with the radio observations (Ogawa 2022, MeteorNews 8,
5), which showed a peak of ZHR = 19 meteors around 15h UT on May 30.  The
peak of brighter Tau Herculid meteors appears to have occurred 1-2 hours
before the main peak, as the less-sensitive Panyu station only detected Tau
Herculids before 14h25m UT.  The more-sensitive Puning station observed a
similar trend, with the peak of brighter meteors (brighter than magnitude +1)
occurring during 13h30m-15h00m UT.  Inspection of the video footages shows
little fragmentation of the detected meteors, which contrasts the highly
fragile meteors from the 1995 trail (Vida et al. 2022, CBET 5126).


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                         (C) Copyright 2022 CBAT
2022 June 11                     (CBET 5132)              Daniel W. E. Green