[Iaude] CBET 5395: NEW METEOR SHOWER IN HERCULES

[quai at eps.harvard.edu]

                                                  Electronic Telegram No. 5395
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau at eps.harvard.edu (alternate cbat at iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


NEW METEOR SHOWER IN HERCULES
     D. Vida, University of Western Ontario; and D. Segon, Croatian Meteor
Network, report an outburst of meteors with a radiant in Hercules:  thirty-two
meteors were observed by the Global Meteor Network low-light video cameras on
2024 Apr. 27 (cf. website URL https://globalmeteornetwork.org/data/ for the
date of 2024 April 27) in a narrow time range between 20h00m-23h40m UTC.  The
shower was independently observed by cameras in eleven different European
countries (Croatia, Slovenia, United Kingdom, Bulgaria, Greece, Czech
Republic, Poland, Romania, Hungary, Spain, and Slovakia).  The meteors were
bright -- most having peak magnitudes ranging from +1.5 to -3.0.  The shower
had a median geocentric radiant with coordinates R.A. = 261.14 deg, Decl. =
+47.28 deg (equinox J2000.0) within a circle with a standard deviation of +/-
1.1 deg, with median sun-centered ecliptic longitude 214.24 deg and latitude
+70.15 deg.  The geocentric velocity was 35.6 +/- 0.9 km/s.  The orbital
elements are those of a long-period comet:  q = 0.9529 +/- 0.0052 AU, e =
0.968 +/- 0.068, i = 55.77 +/- 1.02 deg, Peri. = 206.97 +/- 1.55 deg, Node =
37.819 +/- 0.025 deg (equinox J2000.0).  All meteors appeared during the
solar-longitude interval 37.70-37.85 degrees, with a sharp peak at 37.80 deg.
The bulk of all meteors, a total of 25, was observed in a narrow interval
between 22h00m-22h45m UTC (solar longitude 37.78-37.82 deg).  Using an assumed
mass index of s = 2.0 (the real value was not measured due to small number
statistics), the shower peaked at a ZHR of 6.7 +/- 1.5 meteors/hour.  The
parent-body search did not return any candidates for a Southworth-Hawkins "D"
criterion value < 0.35 (Southworth and Hawkins 1963, Smithsonian Contrib. to
Ap. 7, 261).
     P. Jenniskens writes that this new meteor shower has been given the
provisional name "iota Herculids".


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2024 CBAT
2024 May 20                      (CBET 5395)              Daniel W. E. Green