Abstract: On 2022, August 16, the SonotaCo Network Japan detected an outburst from a mean geocentric radiant position at R.A. = 324.9 ± 0.04 deg, Decl. = –11.9 ± 0.3 deg, at the anti-helion source, with geocentric velocity vg = 24.4 ± 0.5 km/s (Equinox J2000). The shower was detected by the SonotaCo network in the Japan among the first data from August 16. The orbit has a low inclination and resembles that of comet 45P/Honda-Mrkos-Pajdusakova.

 

Introduction

The SonotaCo Network Japan have detected an ongoing outburst of meteors with a low inclined orbit in the anti-helion source. See the online discussion in Japanese.

 

Observations

A total of 8 meteors were triangulated between 2022, Aug. 12, 13h22m and 2022, Aug. 16, 19h14m UT, but that does not mark the end of the shower activity as the activity is still ongoing when this report was written. The radiant around λʘ = 143.4° was centered on the median geocentric position R.A. = 324.9 ± 0.04°, Decl. = –11.9 ± 0.3°, with a geocentric speed vg = 24.4 ± 0.5 km/s (Equinox J2000). This is on the border of Aquarius and Capricorn (Figure 1). The median orbital elements based on four accurate meteors (Table 1 and Figure 2) are:

  • a = 3.03 AU,
  • q = 0.554 ± 0.005 AU,
  • e = 0.816 ± 0.015,
  • i = 1.61 ±0.19°,
  • ω = 270.5 ± 0.12°,
  • Ω = 143.4 ± 0.15°.

Table 1 – SonotaCo meteor orbits and the average orbit.

Local time-JST α
(°)		 δ
(°)		 vg (km/s) a
(AU)		 q
(AU)		 e i
(°)		 ω
(°)		 Ω
(°)		 MA Hb
(km)		 He
(km)
20220816_193802 324.8 –12.2 23.7 2.87 0.556 0.806 1.4 270.5 143.2 –2.3 94.6 84.4
20220816_234642 324.9 –12.0 24.4 3.25 0.549 0.831 1.6 270.5 143.4 –4.3 104.9 77.1
20220817_013405 324.9 –11.7 24.3 3.16 0.550 0.826 1.8 270.6 143.5 –3.6 100.8 81.4
20220817_041433 324.9 –11.7 23.5 2.81 0.560 0.801 1.7 270.3 143.6 –2.7 93.5 76.5
Average 324.9 –11.9 23.9 3.03 0.554 0.816 1.6 270.5 143.4 –3.2 98.4 79.9
S.D. 0.0 0.3 0.5 0.22 0.005 0.015 0.2 0.1 0.1 0.9

Parent body

Jenniskens P. (2022) suggested that this orbit resembles that of lost comet D/1770 L1 (Lexell), during its returns in 1770 and 1776 with a = 3.15 AU, q = 0.674 AU, e = 0.786, i = 1.55 deg, ω = 225.0°, and Ω = 134.5°. Mainly the argument of perihelion differs significantly. But comparing other orbits, there is another possible parent body matching the orbit better, which is 45P/Honda-Mrkos-Pajdusakova.

  • a = 3.03 AU,
  • q = 0.533 AU,
  • e = 0.824,
  • i = 2.60°,
  • ω = 272.8°,
  • Ω = 142.4°.

Fgure 1 – The radiants as spotted in 4 different nights.

 

Fgure 2 – Meteor shower orbit and the orbit of 45P.

 

 

Acknowledgment

SonotaCo Network Japan contributed to this report: 4 meteors were detected.

 

Reference

Jenniskens P. (2022). CBET 5159. Ed.: D. W. E. Green. Cambridge: Central Bureau for Astronomical Telegrams.