Electronic Telegram No. 3503
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 EV_9 (SPACEWATCH)
     An apparently asteroidal object discovered on images taken by T. H.
Bressi with the Spacewatch 0.9-m f/3 reflector (+ CCD mosaic) on Mar. 2
(discovery observations tabulated below) was linked to Mar. 5 astrometry from
the XuYi Station of Purple Mountain Observatory at the Minor Planet Center by
auto-linking routines, and the observations were published on MPS 457939 on
March 10 with the designation 2013 EV_9.  Recent observations by CCD
astrometrists elsewhere have shown this object to show cometary appearance.
H. Sato (Tokyo, Japan; remotely with a 0.51-m f/6.8 astrograph of the
iTelescope observatory located at Siding Spring, NSW) reports that ten stacked
60-s exposures taken on Apr. 28.4 UT show a strongly condensed coma 10" in
diameter with V-band magnitude 18.2, as measured within a circular aperture of
radius 8".2.  Luca Buzzi (Varese, Italy) reports that Tomas Vorobjov found a
5" coma and a hint of a tail in p.a. 120 deg on eighteen stacked 120-s images
taken on Apr. 19.2 using the Western Kentucky University 1.3-m f/13 reflector
located at Kitt Peak; fifty-four stacked 120-s exposures from Apr. 30.17-30.27
reveal a coma 5" x 5" and a tail 15" long in p.a. 120 degrees.  Buzzi also
reports that four stacked 60-s images taken by W. Ryan (Magdalena Ridge
Observatory 2.4-m f/8.9 reflector) on May 1.21 (measured by Buzzi, S.
Foglia, and Ryan) show a coma 10" wide that is clearly extended to the
southeast.  Thirty-one stacked images obtained on May 1.1 by R. Holmes
(Astronomical Research Institute, 0.76-m f/4 astrograph; measured by Buzzi,
Foglia, and Vorobjov) show clearly a softer aspect respect to stars, with a
15" coma elongated to the southeast.  Buzzi adds that eight stacked 60-s
images taken remotely by Americo Watkins with the Mt. Lemmon 0.81-m f/7
reflector (as part of the Sierra Stars Observatory Network) on Apr. 30.1
show a 6" x 5" coma extended to the east.

     2013 UT             R.A. (2000) Decl.       Mag.   Observer
     Mar.  2.27780   11 50 05.01   + 5 11 21.5   19.2   Bressi
           2.29544   11 50 04.80   + 5 11 35.7   19.7     "
           2.31311   11 50 04.48   + 5 11 50.2   19.4     "

The available astrometry -- including prediscovery observations from Feb. 2 and
(Spacewatch) and Feb. 14 (Catalina Sky Survey) -- together with the following
elliptical orbital elements by G. V. Williams and an ephemeris, appear on MPEC
2013-J07.

                    Epoch = 2013 Apr. 18.0 TT
     T = 2013 Apr.  7.16359 TT        Peri. =  22.10380
     e = 0.4857216                    Node  = 161.22395 2000.0
     q = 2.1252250 AU                 Incl. =  14.46825
       a =  4.1324405 AU   n = 0.11732597   P =   8.40 years


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

                         (C) Copyright 2013 CBAT
2013 May 2                       (CBET 3503)              Daniel W. E. Green