Electronic Telegram No. 5601
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
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Prepared using the Tamkin Foundation Computer Network


CHI CYGNID METEOR SHOWER 2025
     P. Jenniskens, SETI Institute and NASA Ames Research Center; and M.
Breukers and C. Johannink, Cameras for Allsky Meteor Surveillance (CAMS),
BeNeLux, report that the chi Cygnids meteor shower (IAU shower #757) was
detected this past week (cf. map at website URL http://cams.seti.org/FDL/ for
dates of 2025 Aug. 20-31).  Based on past returns, the shower is expected to
increase in activity gradually until a peak around Sept. 14, followed by a
rapid decline (cf. Jenniskens 2023, Atlas of Earth's Meteor Showers, p. 83).
This episodic shower was last seen in 2010, 2015, and 2020.  The return in
2025 establishes a five-year periodicity, which suggests that these meteoroids
are trapped in the 7:3 mean-motion resonance with Jupiter (period of 5.08 yr).
The parent Jupiter-family comet is not known, but likely has a semi-major axis
near 2.96 AU, q about 0.99 AU, e about 0.65, i about 23 degrees, Peri. about
194 degrees, Node about 185 degrees, and longitude of perihelion close to 21
degrees.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2025 CBAT
2025 September 3                 (CBET 5601)              Daniel W. E. Green