A meteor outburst detected in the southern hemisphere between September 15 and 26 has been confirmed as a previously unknown meteor shower and is now designated as gamma-Horologii meteor shower.
The outburst was recorded by the Cameras for Allsky Meteor Surveillance (CAMS) network, with contributions from stations in South Africa, Namibia, Chile, New Zealand, Australia, and the United Arab Emirates. Triangulated meteors showed rising activity beginning at solar longitude 169°.
The shower’s radiant in sun-centered coordinates is located at λ = 159.4° ± 1.0° and β = -70.8° ± 0.7°. In geocentric coordinates, the radiant lies near the star gamma Horologii, centered at right ascension 40.9° ± 2.0° and declination -66.4° ± 0.3°, with a geocentric velocity of 21.4 ± 0.2 km/s at solar longitude 177.92° ± 0.54°.
The gamma-Horologii shower is not listed in the Atlas of Earth’s Meteor Showers (Jenniskens, 2023), confirming it as a new discovery. Orbital solutions derived from CAMS observations give a semi-major axis of 3.32 AU, a perihelion distance of 0.964 ± 0.002 AU, an eccentricity of 0.710 ± 0.014, an inclination of 31.9° ± 0.4°, an argument of perihelion of 25.4° ± 0.6°, and an ascending node of 357.93° ± 0.54° (J2000.0).
The orbits yield a Tisserand parameter of 2.52 ± 0.07, suggesting a parent body of the Jupiter-family comet type. Jupiter-family comets are short-period comets with orbits influenced by Jupiter’s gravity, and they are a common source of meteoroid streams that produce annual showers.
The identification of a new shower of this type adds to the catalog of known streams and provides insight into the fragmentation and dust production history of its parent body.
Continued monitoring is expected to refine the activity profile of the new stream and clarify whether it represents a recurring annual meteor shower or a transient outburst.
References:
1 Electronic Telegram No. 5614 – Harvard/CBAT – Accessed October 2, 2025