[IAUC] IAUC 9226: C/2011 Q1; C/2010 X1 [25139-2012/04-R1]

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                                                  Circular No. 9226
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 C/2011 Q1 (PANSTARRS)
     As first announced on CBET 2790, R. Wainscoat, M. Micheli, H.
Hsieh, and L. Denneau report the discovery of an apparent comet on
images taken with the 1.8-m "Pan-STARRS 1" telescope at Haleakala
(discovery observation tabulated below); Wainscoat notes that the
object has a distinctly extended point-spread function (PSF), with
a core having FWHM approximately 1".2 and nearby stars having a PSF
of approximately 1".0.  After posting on the Minor Planet Center's
NEOCP webpage, other CCD astrometrists have also noted cometary
appearance.  L. Buzzi, Varese, Italy, notes that stacked images
taken around Aug. 21.98-22.00 UT with a 0.60-m reflector show a 8"
compact coma (red mag 18.7) with a FWHM around 30 percent larger
than that of nearby stars; a 30" tail is seen around p.a. 340 deg,
but it is difficult to estimate due to background nebulosity in the
area.  Stacked CCD images taken around Aug. 22.1 by R. Holmes
(Ashmore, IL, USA; 0.61-m astrograph; measured by S. Foglia, L.
Buzzi, and T. Vorobjov) show the object to have an elongated coma
of size 6" x 12" and mag 19.1-19.3, elongated toward p.a. 350 deg,
where there is a 20"-long tail.

     2011 UT             R.A. (2000) Decl.       Mag.
     Aug. 20.44054   20 48 02.41   +30 21 49.2   20.6

The early astrometry appears on MPEC 2011-Q12; the following
parabolic orbital elements by G. V. Williams are from 42
observations spanning Aug. 20-Sept. 5:

     T = 2011 July 17.9572 TT         Peri. = 137.3884
                                      Node  = 142.2764  2000.0
     q = 6.784471 AU                  Incl. =  94.8234


COMET C/2010 X1 (ELENIN)
     M. Mattiazzo, Castlemaine, Victoria, Australia, reports that,
following a notable fading of this comet from Aug. 17 to 22, he
finds this comet to be continuing to fade and disperse in CCD
images, as if it is in the process of disintegrating; his CCD image
taken on Aug. 27.37 UT reveals that the nuclear condensation has
spread out into an elongated, diffuse smudge, adding that it is
reminiscent of comet C/1999 S4.  R. H. McNaught confirms this
appearance on images taken with the Uppsala Schmidt telescope at
Siding Spring, noting that there is absolutely no condensation
visible, making astrometry very difficult.

                      (C) Copyright 2011 CBAT
2011 September 11              (9226)            Daniel W. E. Green