Electronic Telegram No. 4363
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
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URSIDS METEORS 2016
     P. Jenniskens, SETI Institute and NASA Ames Research Center, reports
that the earth encountered the A.D. 1076 ejected dust of comet 8P/Tuttle on
2016 Dec. 22d11h35m UTC, at solar longitude 270.825 +/- 0.010 deg (equinox
J2000.0).  The Ursid meteor shower rates increased during the time
encompassing the span of solar longitude 0.13 +/- 0.03 degrees (full-width-
at-half-maximum).  In California, the "Cameras for Allsky Meteor Surveillance"
project detected 3, 5, 5, 3, 2, 0, 0, 2, 4, 2, 2, 4, 5, 6, 3, 7, 8, 9, 21,
24, 16, 16, 15, 15, 7, 7, and 5 Ursids, in intervals of 0.02 degrees starting
at 270.44 degrees solar longitude, during a clear and transparent night.
Meteors radiated from a geocentric radiant R.A. = 219.1 +/- 3.9 deg, Dec. =
+75.6 +/- 0.9 deg, with velocity v_g = 33.1 +/- 0.9 km/s.
     E. Lyytinen, Helsinki, Finland, had calculated an encounter with the
A.D. 1076 dust ejecta of 8P/Tuttle at 2016 Dec. 22d10h05m UTC, at solar
longitude 270.760 deg (cf. Jenniskens 2006, *Meteor Showers and Their
Parent Comets*, p. 641).
     H. Sugimoto of Japan first noticed elevated meteor rates during
270.72-271.05 degrees solar longitude in compiled radio forward-meteor-
scatter observations by the worldwide online Radio Meteor Observatory (cf.
website URL http://www5f.biglobe.ne.jp/~hro/Flash/2016/URS/index.html).
F. Verbelen at Kampenhout, Belgium, reported a weighted averaged hourly
count of overdense reflections centered on solar longitude 270.825 +/-
0.010 degrees, with FWHM = 0.20 +/- 0.05 degrees, in good agreement (cf.
website URL http://www.imo.net/enhanced-radio-activity-of-2016-ursids/).
This activity is now confirmed to have come from the Ursid meteor shower.


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                         (C) Copyright 2017 CBAT
2017 February 20                 (CBET 4363)              Daniel W. E. Green