Electronic Telegram No. 3495
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 C/2013 H2 (BOATTINI)
     A. Boattini reports his discovery of a comet (discovery observations
tabulated below) on CCD images taken with the Catalina Sky Survey's 0.68-m
Schmidt telescope; he noted that four co-added 30-s exposures show a strongly
condensed coma about 10-12" in diameter with no evident tail visible against a
rich star background.  Follow-up images obtained by Boattini with the Mt.
Lemmon 1.5-m reflector on Apr. 23.3-23.5 UT show a strong central condensation
with a 10" coma and a very faint fan-shaped tail extending for about 40" in
p.a. 140-165 deg, as seen in four co-added 50-s exposures.  After the object
was posted on the Minor Planet Center's NEOCP webpage, other CCD astrometrists
have commented on the cometary appearance.  H. Sato (Tokyo, Japan; remotely
using an iTelescope 0.51-m f/6.8 astrograph at Siding Spring, NSW; eight
stacked 60-s exposures; Apr. 22.6) found a strongly condensed coma 10" in
diameter, with V-band magnitude 18.1 as measured within a circular aperture of
radius 6".5, and showing a faint fan-like tail 15" long toward p.a. 135 deg.
Luca Buzzi (Varese, Italy; 0.38-m f/6.8 reflector; Apr. 25.1) writes that
stacked images obtained in good seeing but in a bright sky show a softer
aspect with respect to stars and a tail 10" long in p.a. around 130 deg.
Sergio Foglia notes that 30 stacked 30-s images obtained by R. Holmes (Ashmore,
IL, USA; 0.81-m f/4 astrograph; Apr. 25.35-25.36) show a 6" round coma and
an 8".5 tail in p.a. 162 deg.

     2013 UT             R.A. (2000) Decl.       Mag.   Observer
     Apr. 22.44551   17 09 31.32   - 7 43 06.6   17.6   Boattini
          22.45227   17 09 31.14   - 7 43 04.1   17.6     "
          22.45905   17 09 30.81   - 7 43 02.3   17.5     "
          22.46586   17 09 30.63   - 7 43 00.4   17.4     "

The available astrometry, the following very preliminary elliptical orbital
elements, and an ephemeris appear on MPEC 2013-H45.

     T = 2011 Mar. 27.7999 TT         Peri. = 259.5192
     e = 0.774571                     Node  = 255.1185  2000.0
     q = 2.481260 AU                  Incl. = 108.2292
       a = 11.006857 AU    n = 0.0269904    P =  36.5 years


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2013 CBAT
2013 April 25                    (CBET 3495)              Daniel W. E. Green