%0 Journal Article
%T Characterisation of the Perseid meteoroid stream through SPOSH observations between 2010¨C2016
%A A. Christou
%A A. Margonis
%A J. Oberst
%J -
%D 2019
%R 10.1051/0004-6361/201834867
%X We have characterised the Perseid meteoroid stream from data acquired in a series of observing campaigns between 2010 and 2016. The data presented in this work were obtained by the Smart Panoramic Optical Sensor Head (SPOSH), an all-sky camera system designed to image faint transient noctilucent phenomena on dark planetary hemispheres. For the data reduction, a sophisticated software package was developed that utilises the high geometric and photometric quality of images obtained by the camera system. We identify 934 meteors as Perseids, observed over a long period between late July (~124¡ã) and mid-to-late August (~147¡ã). The maximum meteor activity contributing to the annual shower was found at <i>¦Ë<i/><sub>¡Ñ<sub/> = 140¡ã.08 ¡À 0¡ã.07. The radiant of the shower was estimated at RA = 47¡ã.2 and Dec = 57¡ã.5 with a median error of 0¡ã.6 and 0¡ã.2, respectively. The mean population index of the shower between solar longitudes of 120¡ã.68 and 145¡ã.19 was <i>r<i/> = 2.36 ¡À 0.05, showing strong temporal variation. A predicted outburst in shower activity for the night of August 11¨C12, 2016 was confirmed, with a peak observed 12.75 hr before the annual maximum at 23:30 ¡À 15¡ä UT. We measure a peak flux of 6.1 ¡Á 10<sup>£¿4<sup/> km<sup>£¿2<sup/> hr<sup>£¿1<sup/> for meteoroids of mass 1.6 ¡Á 10<sup>£¿2<sup/> g or more, appearing in the time period between 23:00 and 00:00 UT. We estimate the measured flux of the outburst meteoroids to be approximately twice as high as the annual meteoroid flux of the same mass. The population index of <i>r<i/> = 2.19 ¡À 0.08, computed from the outburst Perseids in 2016, is higher than the value of <i>r<i/> = 1.92 ¡À 0.06 derived from meteors observed in 2015 belonging to the annual Perseid shower which was active near the time of the outburst. A dust trail with an unusually high population index of <i>r<i/> = 3.58 ¡À 0.24 was encountered in 2013 between solar longitudes 136¡ã.261 and 137¡ã.442. The relatively high <i>r<i/>-value implies an encounter with a dust trail rich in low-mass particles
%U https://www.aanda.org/articles/aa/full_html/2019/06/aa34867-18/aa34867-18.html