Electronic Telegram No. 5347
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
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Prepared using the Tamkin Foundation Computer Network


IOTA CENTAURID METEOR SHOWER
     P. Jenniskens, SETI Institute and NASA Ames Research Center, reports that
the iota Centaurid meteors (IAU shower no. 919), showed stronger than usual
activity during 2024 Jan. 21-26 (corresponding to solar longitudes 301.0 to
306.0 deg; equinox J2000.0; see the map at URL http://cams.seti.org/FDL/ for
dates of Jan. 23 and 24).  Forty-eight iota Centaurids were triangulated by
CAMS New Zealand, as coordinated by J. Baggaley (University of Canterbury) and
J. Scott (University of Otago); 34 shower meteors by CAMS Australia, via H.
Devillepoix (Curtin University) and D. Rollinson; 16 shower meteors by CAMS
Chile, via S. Heathcote and T. Abbott (NOIRLAB/Cerro Tololo) and E. Jehin
(University of Liege), 2 shower meteors by a mostly clouded CAMS Namibia, via
T. Hanke (H.E.S.S. Collaboration), and 1 shower meteor by the northern-
hemisphere United Arab Emirates Astronomical Camera Network, via M. Odeh
(International Astronomical Center).  The annual ratio of triangulated iota
Centaurids to all sporadic meteors for these networks was, starting in 2020:
0.0037 +/- 0.0009, 0.0038 +/- 0.0010, 0.0018 +/- 0.0007, 0.0034 +/- 0.0009,
and 0.0145 +/- 0.0015.  Rates were above normal, peaking at 302.4 +/- 0.1 deg,
with a full-width-at-half maximum duration of about 1.6 deg.  The meteors
radiated from a geocentric radiant at R.A. = 200.6 deg, Decl. = -40.3 deg,
with geocentric velocity 63.7 km/s.  Median orbital elements were a = 4.7 AU,
q = 0.979 +/- 0.005 AU, e = 0.790 +/- 0.086, i = 129.4 +/- 1.5 deg, Peri =
350.8 +/- 3.4 deg, Node = 122.4 +/- 1.7 deg (equinox J2000.0).  This is
normally a minor shower active between Jan. 16 and 25, with an earlier peak
at solar longitude 299.5 deg (cf. Jenniskens 2023, Atlas of Earth's Meteor
Showers, p. 525).  The parent body is unknown.  The short semi-major axis and
long-duration activity suggest that the 2024 activity might be dust from a
1P/Halley-type comet trapped in the 1:1 mean-motion resonance with Jupiter.
Indeed, the shower was also detected by northern-hemisphere CAMS and SonotaCo
stations, with a low radiant elevation, in 2013 during solar longitudes
300.6-302.5 deg.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2024 CBAT
2024 February 12                 (CBET 5347)              Daniel W. E. Green