[IAUC] IAUC 9249: C/2011 Y3 [25139-2012/04-R1]

[quai en eps.harvard.edu]

                                                  Circular No. 9249
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
New postal address:  Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
CBATIAU en EPS.HARVARD.EDU           ISSN 0081-0304
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 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 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 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 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
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 deg.  R. Ligustri (Talmassons, Udine,
Italy) finds the object to be diffuse on images taken on Dec. 27.3
with a 0.50-m 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 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
          25.26127    5 48 17.28   +26 11 38.7   18.9     "
          25.34135    5 48 13.96   +26 12 09.1   19.4     "

The initial astrometry appeared on MPEC 2011-Y50; revised parabolic
orbital elements from MPEC 2011-Y66 from 42 observations, Dec.
25-29:

     T = 2011 Mar. 26.3979 TT         Peri. = 317.1089
                                      Node  =  86.0061  2000.0
     q = 3.780155 AU                  Incl. =  40.0569

                      (C) Copyright 2011 CBAT
2011 December 31               (9249)            Daniel W. E. Green