Publication Date:
2015-11-28
Description:
We present October Draconid meteor head echo observations with the Shigaraki middle and upper atmosphere (MU) radar in Japan. Prominent activity of 2012 October Draconids occurred on October 8 between 16:20 ut and 17:40 ut . Around the peak time (13–20 h ut ), the MU radar recorded 51 Draconid head echoes with precise orbit determinations. The weighted mean geocentric radiant during this time interval was located at right ascension α g = 262 $_{.}^{\circ}$ 5 ± 0 $_{.}^{\circ}$ 5 and declination g = +55 $_{.}^{\circ}$ 8 ± 0 $_{.}^{\circ}$ 3(epoch J2000.0). The weighted mean geocentric velocity was 20.6 ± 0.3 km s – 1 . Both are in good agreement with model predictions. Although the models predicted no strong visually detectable activity, our head echo observations showed that the peak activity in 2012 was higher than that of the previous outburst in 2011. Based on the distribution of radar cross-section for the Draconid meteor head echoes, the outburst in 2012 was due to meteoroids with lower masses (fainter meteors) than that in 2011.
Print ISSN:
0035-8711
Electronic ISSN:
1365-2966
Topics:
Physics
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