Electronic Telegram No. 3652
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


SEPTEMBER EPSILON PERSEIDS 2013
     P. Jenniskens, SETI Institute, reports that the September epsilon
Perseids (IAU abbreviation SPE, IAU shower number 208), normally having their
highest activity between Sept. 8 and 10, had an outburst of mostly bright
(magnitude +4 to -8) meteors on Sept. 9d21h30m-9d23h20m UT.  Jarmo Moilanen
in Finland detected 25 SPE meteors and 7 sporadic meteors that night using a
low-light-level video camera, with highest SPE rates (3 per minute) centered
at Sept. 9d22h22m +/- 09m UT.  Ilkka Yrjola (Kuusankoski, Finland) detected
elevated radio forward-meteor reflections between Sept. 9d21h30m and 9d23h20m
UT.  SPE rates were back to normal between Sept. 10d3h and 10d8h UT in
low-light video observations by D. Samuels, D. Drumheller, and J. Head,
participating in the NASA CAMS meteor shower surveillance project in
California.  A similar outburst was observed in 2008 (cf. CBET 1501).
     Jenniskens adds that, in response, Esko Lyytinen (Helsinki, Finland)
calculated the perturbations of a one-revolution long-period comet dust trail
in an orbit based on measurements of the 2008 SPE outburst, assuming that the
dust was ejected before the year 1800 AD, and calculated a second encounter
with the earth on 2013 Sept. 9d22h15m UT (solar longitude 167.200 deg), in
good agreement with the time of the observed outburst this year.  This time
around, the dust trail was passed at a distance of only 0.00036 AU further
out than in 2008.

     Quanzhi Ye, University of Western Ontario, writes that no unusual
activity from these meteors was detected during approximately Sept. 9.67-9.94
UT (when twilight commenced) on images obtained with the two all-sky cameras
operated by Xing Gao at Xingming Observatory near Xinjiang, China, which take
one frame every five minutes (limiting magnitudes about 6 and 4).


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2013 CBAT
2013 September 13                (CBET 3652)              Daniel W. E. Green