Electronic Telegram No. 2959
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/2011 Y3 (BOATTINI)
     A. Boattini reports his discovery of another comet on CCD images taken
with the Mount Lemmon 1.5-m reflector (discovery observations tabulated below),
the object noted as being very diffuse with central condensation; four 30-s
exposures show a 6" coma and a wide fan-shaped tail about 30" long in p.a.
240-245 deg.  After posting on the Minor Planet Center's NEOCP webpage, other
CCD astrometrists have also noted the object's cometary appearance.
H. Sato (Tokyo, Japan; remotely using a 0.43-m f/4.5 reflector at the RAS
Observatory, Nerpio, Spain, on Dec. 25.8 UT) found a diffuse 17" coma and a
fan-like tail 20" long toward p.a. 225-270 deg; a total V-band magnitude of
19.3 was measured within a circular aperture of radius 8".4.  L. Buzzi
(Varese, Italy; 0.38-m f/6.8 reflector; Dec. 26.0) found a very diffuse 10"
coma and a broad tail at least 25" long in p.a. around 250 deg.  Ten stacked
60-s exposures taken by R. Holmes (Ashmore, IL, USA; 0.61-m f/4.0 astrograph;
measured by L. Buzzi, S. Foglia, and T. Vorobjov) on Dec. 26.3 show a very
diffuse object with a round 15" coma near a bright star; there is also a 20"
tail in p.a. 250 deg.  A. Novichonok (Kondopoga, Russia) reports that four
stacked 300-s images taken remotely by V. Gerke (Moscow, Russia) with the
0.4-m f/8 "Jigit" reflector at the TAU station of Ka-Dar Observatory (near
Nizhniy Arkhyz, Russia) on Dec. 26.7 show a condensed coma of total mag 18.7
and a 0'.6 tail in p.a. 260 deg.  J. Lacruz (Madrid, Spain) writes that images
taken with a 0.40-m Ritchey-Chretien reflector at La Canada on Dec. 26.94-26.96
show a diffuse nuclear region with a round 10" coma and a short fan-like tail
extending about 35" toward p.a. 235.  R. Ligustri (Talmassons, Udine, Italy)
finds the object to be diffuse on images taken on Dec. 27.3 with a 0.50-m
f/4.4 reflector at the RAS Observatory near Mayhill, NM, U.S.A.  Images
acquired by P. Bacci, L. Tesi, and G. Fagioli with a 0.60-m f/4 reflector
on Dec. 27.8 show a diffuse coma of diameter 14" and a tail 22" long in
p.a. 234 deg.

     2011 UT             R.A. (2000) Decl.       Mag.   Observer
     Dec. 25.24063    5 48 18.18   +26 11 30.5   18.9   Boattini
          25.24749    5 48 17.96   +26 11 33.7   19.4     "
          25.25438    5 48 17.71   +26 11 35.7   19.0     "
          25.26127    5 48 17.28   +26 11 38.7   18.9     "
          25.31999    5 48 14.90   +26 12 00.6   19.8     "
          25.33415    5 48 14.25   +26 12 05.9   18.7     "
          25.34135    5 48 13.96   +26 12 09.1   19.4     "

The available astrometry, the following preliminary parabolic orbital elements
by G. V. Williams, and an ephemeris appear on MPEC 2011-Y50.

     T = 2011 Dec.  2.1811 TT         Peri. =   0.2308
                                      Node  =  86.9518  2000.0
     q = 5.554371 AU                  Incl. =  58.5841


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

                         (C) Copyright 2011 CBAT
2011 December 28                 (CBET 2959)              Daniel W. E. Green