[IAUC] IAUC 9210: P/2011 JB_15 [25139-2011/04-R1]

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                                                  Circular No. 9210
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
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Prepared using the Tamkin Foundation Computer Network


COMET P/2011 JB_15 (SPACEWATCH-BOATTINI)
     A. Boattini reports his discovery of a comet on CCD images
obtained with the Mt. Lemmon 1.5-m reflector, noting the object to
have a strong condensation with a 5" coma having a slight
elongation along the northeast-southwest and a faint, wide tail
about 15" long in p.a. 240-260 deg.  After posting on the Minor
Planet Center's NEOCP webpage, this object was identified with an
object reported as apparently asteroidal by the Spacewatch survey
on May 8 and 12 and previously given the designation 2011 JB_15
(MPS 382375).  The discovery observations are tabulated below.
Other CCD astrometrists have reported the following coma diameters:
May 29.3 UT, 5" (S. Foglia, S. Baroni, L. Buzzi, P. Concari, G.
Galli, and M. Tombelli; 21-cm refractor at Tzec Maun Observatory,
Cloudcroft, NM, U.S.A.; round coma of red mag 18.4-18.7); May 29.4
(0.25-m reflector) and May 30.3 (0.50-m reflector), 8" (H. Sato,
Tokyo, Japan, remotely, RAS Observatory, Mayhill, NM, U.S.A.;
condensed coma); May 30.0, about 6" (G. Masi, U. Masi, and G. Luccone,
Ceccano, Italy, 0.43-m reflector; fuzzy, circular coma); May 30.0,
8" (L. Buzzi, Varese, Italy, 0.60-m reflector; compact coma
elongated toward p.a. 250 deg); May 30.3, about 8" (E. Guido and G.
Sostero, 0.25-m reflector, GRAS Observatory near Mayhill; very weak
central condensation); May 30.3 and 31.2, 5" x 8" (R. Holmes,
Ashmore, IL, USA, 61-cm f/4 astrograph; elongated coma with a 15"
tail in p.a. 235 deg; measured by Foglia); May 30.8, about 15" (R.
Ligustri, Udine, Italy, 0.35-m reflector; faint coma elongated
toward p.a. 230 deg); May 31.0, about 7" (Masi, Masi, and Luccone;
slightly elongated toward the northeast-southwest); May 31.0, about
6" (P. Birtwhistle, Great Shefford, Berkshire, England, 0.40-m
reflector; diffuse, possibly extended up to 10" toward the west).
R-band images taken by W. H. Ryan and E. V. Ryan (Magdalena Ridge
Observatory 2.4-m reflector, May 31.3, show a tail in p.a. about
235 deg.

     2011 UT             R.A. (2000) Decl.       Mag.   Observer
     May   8.39074   16 17 11.93   + 2 28 48.5   19.6   Spacewatch
          28.32572   16 08 33.61   + 3 06 47.7   19.1   Boattini

The available astrometry, the following orbital elements by G. V.
Williams, and an ephemeris appear on MPEC 2011-K56.

                    Epoch = 2012 Feb.  3.0 TT
     T = 2012 Jan. 18.1370 TT         Peri. = 110.4593
     e = 0.315392                     Node  = 153.8057  2000.0
     q = 5.028229 AU                  Incl. =  19.1476
       a =  7.344679 AU    n = 0.0495159    P =  19.9 years

                      (C) Copyright 2011 CBAT
2011 May 31                    (9210)            Daniel W. E. Green