Abstract: The predicted outburst of the Aurigid meteor shower (AUR # 00206) occurred during the night of August 31 – September 1, 2021. According to the data from the Belarusian and Ukrainian meteor video networks, the activity profile for this meteor shower during this night could be obtained and it turned out to be twin-peaked. The exact radiant coordinates (RA: 91.06° ± 0.13°, Dec: 39.12° ± 0.07°) and orbital elements of the Aurigids have been calculated for the peak activity of the meteor shower.

 

Introduction

Conditions were quite good in Belarus and Ukraine, despite a low radiant position of about 20° above the horizon (better than in Western Europe). The maximum occurred just after midnight local time. The weather was pretty good for this time of the year. Some cameras did not work due to cloud cover. However, where the sky was clear useful data could be obtained from 18 cameras in Belarus and Ukraine.

Figure 1 – Stacked image of registered Aurigids during the night of August 31 – September 1, 2021 from the camera located in Derazhnoye, Belarus.

 

 

The activity profile

To determine the activity curve of the Aurigids, all individual meteors that radiated precisely from the radiant were collected for the night of August 31 – September 1, 2021 (Figure 2).

Figure 2 – Individual meteors radiating from the Aurigid radiant.

 

Duplicates of paired meteors captured by two or more cameras were discarded from this selection. Thus, 79 unique meteors radiating from the Aurigids’ radiant were collected. The times of meteor appearances were divided into 5- and 10-minute intervals and the numbers of Aurigids per time interval were then plotted on the timeline shown in Figure 3.

Figure 3 – Using 10-minute intervals results in a smoother profile, while the 5-minute intervals show more scatter with several spikes.

 

The graph shows that the increased activity lasted for 40 minutes between 21h15m–21h55m UT. The middle of this interval was at 21h35m UT. However, we can also see that the peak had at least two pronounced sub-maxima with a dip in the middle.

 

Radiant coordinates and orbital elements

Radiant coordinates and orbital elements were calculated with UFOOrbit for multi-station meteors captured by two or more cameras. For greater accuracy, only the best 11 multi-station meteors of quality Q2 and Q3 were used (Figure 4). They all fell within the time interval from 21h22m UT to 23h21m UT.

Figure 4 – The trajectories of multi-station Aurigids of quality Q2 and Q3 plotted on a ground map.

 

Figure 5 shows the radiant positions for multi-station Aurigids on the star map. It should be noted that the area of the radiant was remarkably very small, it is smaller than the lunar disk.

Figure 5 – Radiant positions of 11 multi-station Aurigids with quality Q2 and Q3 plotted on a star map. Note the small size of the radiant area, less than the lunar disk.

 

After calculations and averaging the data of 11 multi-station meteors, the following radiant coordinates and orbital elements (with standard deviations) were obtained for Solar Longitude 158.406°:

  • RA: 91.06° ± 0.13°
  • Dec: 39.12° ± 0.07°
  • vg = 65.3 ± 0.9 km/s
  • q = 0.665 ± 0.014 AU
  • e = 0.948 ± 0.052
  • ω = 107.4° ± 2.9°
  • Ω = 158.41° ± 0.02°
  • i = 148.3° ± 0.3°

 

Figure 6 – The orbits of the Aurigids, left top view on the ecliptic, right side view.

 

 

Conclusion

The outburst of the Aurigid meteor shower occurred as previously predicted centered at 21h35m UT. The peak turned out to be double with a dip in the middle.

Most Aurigids radiated from a compact radiant with a diameter smaller than the size of the lunar disk.

The results obtained, as well the moment of maximum as the shape of the profile with two maxima and a dip in between, agree well with the results of visual and radio observations obtained by other authors (Miskotte, 2021; Ogawa and Sugimoto, 2021).

 

 

Acknowledgments

Many thanks to all participants in the Belarusian and Ukrainian video meteor networks for their dedicated efforts. Grateful for the favorable weather during the opportunity to observe the Aurigids outburst and many thanks to heaven for the inspiration.

Belarusian meteor video network: Andrei Prokopovich, Igor Balyuk, Konstantin Morozov, Sergei Dubrovski and Yury Harachka.

Ukrainian meteor video network: Serhii Bondarenko, Marian Stasiuk and Zlochevskyi Yurii.

 

References

Miskotte K. (2021). “A modest Aurigid outburst in 2021”. eMetN, 6, 526–530.

Ogawa H. and Sugimoto H. (2021). “Aurigids (AUR#00206) 2021 using worldwide radio meteor observations”. eMetN, 6, 574–577.