Electronic Telegram No. 3850 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 COMET P/2013 PE_67 (CATALINA-SPACEWATCH) An apparently asteroidal object found nearly simultaneously last August 9 via the Catalina Sky Survey (observers E. J. Christensen and J. A. Johnson) and with the Spacewatch II reflector at Kitt Peak (observer J. V. Scotti) has been found to show cometary activity in the past month by CCD astrometrists elsewhere. The discovery observations (first published on MPEC 2013-Q15, where it was given the minor planet designation 2013 PE_67) are tabulated below. 2013 UT R.A. (2000) Decl. Mag. Observer Aug. 9.27137 22 03 33.08 - 6 56 22.0 19.5 Christensen 9.27795 22 03 31.39 - 6 56 17.7 19.3 " 9.28469 22 03 29.70 - 6 56 12.5 19.6 " 9.29142 22 03 28.00 - 6 56 08.1 19.8 " 9.37462 22 03 06.76 - 6 55 12.1 19.6 " 9.38108 22 03 05.07 - 6 55 07.6 19.4 " 9.38757 22 03 03.42 - 6 55 03.3 19.4 " 9.39405 22 03 01.72 - 6 54 58.6 19.0 " 9.45431 22 02 46.35 - 6 54 17.3 20.3 " 9.45998 22 02 44.95 - 6 54 14.6 19.6 " 9.46168 22 02 44.52 - 6 54 12.8 19.3 Scotti 9.46284 22 02 44.22 - 6 54 12.1 19.2 " 9.46399 22 02 43.93 - 6 54 11.3 19.1 " 9.46563 22 02 43.47 - 6 54 10.1 19.1 Christensen H. Sato, Tokyo, Japan, was the first to report a diffuse appearance to the Central Bureau, on stacked luminance-filter images obtained on 2014 Mar. 9.2 (0.32-m f/8 astrograph at the iTelescope Observatory near Nerpio, Spain) and Mar. 10.5 UT (0.43-m f/6.8 astrograph at the iTelescope Observatory near Mayhill, NM, USA); the first night he reported a moderately condensed coma 10" in diameter with no tail and magnitude 18.3 as measured within a circular aperture of radius 5".8, while on the second night he an apparent outer coma 30" in diameter of mag 18.0 as measured within a circular aperture of radius 15".3 and a possible faint tail 3' long toward p.a. 200 degrees. Luca Buzzi, Varese, Italy, stacked images obtained with a 0.60-m f/4.6 reflector on Mar. 10.15-10.18 that revealed a diffuse object with a central condensation surrounded by a coma around 14" in size, possibly elongated to the west; Buzzi's follow-up images on Mar. 29.1 show a central condensation surrounded by a coma around 18" in size, the coma having a less-defined shape toward the southeast. William H. Ryan reports that R-band images taken on Mar. 11.34- 11.37 with the Magdalena Ridge Observatory 2.4-m f/8.9 reflector show a distinct coma > 8" in size, elongated toward p.a. about 200 deg; Ryan's follow-up images on Apr. 9.3 again show a distinct coma extended toward p.a. about 140 deg. Christensen obtained further images with the Catalina 0.68-m Schmidt on Apr. 8.44-8.46 UT, noting that four stacked 30-s images show a weakly condensed coma with a faint 25" tail toward p.a. 150 deg, with mag 18.7-19.1. S. Foglia writes that eighty stacked 60-s images obtained with a 0.61-m f/4.5 astrograph by R. Holmes (Ashmore, IL, USA) on Apr. 9.4 show a round coma 8" in diameter and a wide tail 15" long in p.a. 160 deg. R. Ligustri (Talmassons, Udine, Italy) stacked fifteen 60-s images taken on Apr. 9.4 with an iTelescope 0.50-m f/4.5 reflector, finding a coma of size about 24". Stacked images taken the Konkoly Observatory 0.60-m Schmidt telescope at Piszkesteto, Hungary, on Apr. 9.80 by K. Sarneczky and I. Papp show a 10" coma and two tails -- a 20"-long diffuse tail in p.a. about 120 deg and a 20"-long thin tail in p.a. about 180 deg. The available astrometry (including pre-discovery Pan-STARRS1 astrometry from 2013 Aug. 3.5 and 8.5), the following orbital elements by G. V. Williams, and an ephemeris appear on MPEC 2014-G64. Epoch = 2013 Dec. 14.0 TT T = 2013 Dec. 9.30121 TT Peri. = 59.48416 e = 0.9667932 Node = 325.96144 2000.0 q = 1.8470730 AU Incl. = 116.71780 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2014 CBAT 2014 April 10 (CBET 3850) Daniel W. E. Green