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Electronic Telegram No. 3853 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 NEW METEOR SHOWER: APRIL ALPHA CAPRICORNIDS P. Jenniskens, SETI Institute, forwards a report by Touru Kanamori (Tokyo, Japan) of the detection a new meteor shower radiating from near the star alpha Cap between 2014 Apr. 7d16h59m and 7d19h33m UT, first noticed by SonotaCo Video Meteor Network member Masayuki Shimoda. Orbital elements calculated from triangulated video observations by numerous SonotaCo Network members and by members of the Sanbonmatsu high school show fifteen meteoroid orbits radiating from R.A. = 304.0 +/- 3.4 deg, Decl = -12.6 +/- 1.6 deg (equinox 2000.0) with geocentric velocity 69.1 +/- 1.5 km/s. Fifteen out of a total of 73 observed multi-station meteors were assigned to this stream. The mean orbital elements have semi-major axis around 85 AU, q = 0.80 +/- 0.07 AU, e = 0.98 +/- 0.13, argument of perihelion = 124 +/- 10 deg, Node = 17.66 +/- 0.04 deg, and i = 167 +/- 6 deg. No meteors were detected in the period Apr. 4-6 (118 orbits) and Apr. 8-10 (53 orbits). Jenniskens adds that no candidate shower members were detected among 334 meteoroid orbits measured in the solar longitude interval 16.0-19.0 deg in 2011-2012 by the California All-sky Meteor Surveillance project, which implies that this is a periodic shower. The meteoroids move in a long-period comet orbit, suggesting that this event was a meteor outburst due to the crossing of a one-revolution dust trail of a yet-to-be-discovered long-period comet. If so, M. Sato (National Astronomical Observatory of Japan) calculated that this dust trail was in the earth's path also on Apr. 7 UT in 1980, 1990, 2001, and 2004. Future encounters may happen on Apr. 7 UT in 2025 and 2032. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2014 CBAT 2014 April 12 (CBET 3853) Daniel W. E. Green