New Long-Duration Meteor Shower Over Southern Hemisphere

Electronic Telegram No. 5614

ONGOING METEOR OUTBURST OVER SOUTHERN HEMISPHERE

Issued September 27, 2025.

P. Jenniskens, SETI Institute and NASA Ames Research Center; T. Cooper and P. Mey, Cameras for Allsky Meteor Surveillance (CAMS) low-light video survey, South Africa; T. Hanke and E. Fahl, CAMS Namibia; S. Heathcote, E. Jehin, and T. Abbott, CAMS Chile; J. Scott and W. J. Baggaley, CAMS New Zealand; D. Rollinson and H. Devillepoix, CAMS Australia; and M. Odeh, United Arab Emirates Astronomical Camera Network, report a meteor outburst of a previously unknown shower in the southern hemisphere this past week, possibly ongoing. Starting at solar longitude 169 deg, in steps of 1 deg, the following number of shower members were triangulated: 1, 0, 0, 7, 2, 1, 2, 3, 6, 10. These have a compact radiant in sun-centered coordinates lambda = 159.4 +/- 1.0, beta = -70.8 +/- 0.7 deg. The geocentric radiant is near the star gamma Horologii, centered at R.A. = 40.9 +/- 2.0 deg, Decl. = -66.4 +/- 0.3 deg, with geocentric velocity 21.4 +/- 0.2 km/s around solar longitude 177.92 +/- 0.54 deg (cf. website URL: http://cams.seti.org/FDL/ for the dates of 2025 Sept. 15-26).  This gamma-Hor shower is not listed in the Jenniskens (2023) *Atlas of Earth's Meteor Showers*. Orbital elements are centered at a = 3.32 AU, q = 0.964 +/- 0.002 AU, e = 0.710 +/- 0.014, i = 31.9 +/- 0.4 deg, Peri. = 25.4 +/- 0.6 deg, Node = 357.93 +/- 0.54 deg (equinox J2000.0). These orbits have a Tisserand parameter of 2.52 +/- 0.07, suggesting a parent Jupiter-family comet.

NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars.

(C) Copyright 2025 CBAT, 2025 September 27 (CBET 5614), Daniel W. E. Green