[IAUC] IAUC 9214: C/2011 L3; 29P [25139-2011/04-R1]

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                                                  Circular No. 9214
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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CBATIAU en EPS.HARVARD.EDU           ISSN 0081-0304
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Prepared using the Tamkin Foundation Computer Network


COMET C/2011 L3 (McNAUGHT)
     Robert H. McNaught reports his discovery of a comet (discovery
observation tabulated below) on CCD images taken with the 0.5-m
Uppsala Schmidt telescope at Siding Spring; on the discovery images,
the object showing a moderately condensed 18" coma and a diffuse
0'.7 tail in p.a. 240 deg.  After posting on the Minor Planet
Center's 'NEOCP' webpage, other CCD astrometrists have commented on
the object's cometary appearance.  H. Sato (Tokyo, Japan; remotely
using a 0.50-m f/4.5 reflector at the RAS Observatory near Mayhill,
NM, U.S.A., June 4.4 UT) finds a coma of diameter 40" and total red
mag 15.2 with a faint 40" tail in p.a. 225 deg.  S. Foglia writes
that stacked images taken by S. Baroni, L. Buzzi, P. Concari, G.
Galli, M. Tombelli, and himself on June 4.7 with a 0.18-m f/2.8
reflector (at the Tzec Maun Observatory near Moorook, Australia)
show an elongated coma of size 30" x 15", elongated in p.a. 225
deg.  Stacked images taken by R. Holmes (Ashmore, IL, USA, 0.61-m
f/4 astrograph, June 6.4) show a 45" coma and a 60" tail in p.a.
235 deg (measured by S. Foglia and T. Vorobjov).  Paul Camilleri
remotely used a 0.35-m f/3.8 reflector of the Tzec Maun Observatory
(near Cloudcroft, NM, U.S.A.) on June 5.4; his stacked images show
a coma diameter of about 10" with a faint, fan-shaped tail about 5"
long.  Stacked unfiltered CCD images taken remotely by E. Guido and
G. Sostero (0.25-m f/3.4 reflector, GRAS Observatory near Mayhill,
June 5.4) reveal a strong central condensation and a coma nearly
25" in diameter that is elongated toward p.a. 230 deg.  Images
taken by A. C. Gilmore and P. M. Kilmartin with the Mt. John 1.0-m
f/7.7 reflector on June 6.7 show a coma diameter of about 15" with
a 45" tail in p.a. 230 deg.

     2011 UT             R.A. (2000) Decl.       Mag.   Observer
     June  3.76774   22 42 58.77   -15 32 19.8   16.3   McNaught

The available astrometry, the following preliminary parabolic
orbital elements by G. V. Williams, and an ephemeris appear on MPEC
2011-L28.

     T = 2011 Aug. 10.347 TT          Peri. =  27.632
                                      Node  = 307.760   2000.0
     q = 1.92498 AU                   Incl. =  87.092


COMET 29P/SCHWASSMANN-WACHMANN
     Visual total-magnitude estimates by J. J. Gonzalez, Leon,
Spain (0.20-m reflector):  Apr. 27.02 UT, 11.3; May 22.96, 11.8;
June 1.94, 10.2.

                      (C) Copyright 2011 CBAT
2011 June 6                    (9214)            Daniel W. E. Green