[IAUC] IAUC 9198: COMET C/2011 C1 (McNAUGHT); 2011 CQ_1; C/2009 U13, C/2009 U14, C/2009 Y5-Y8 [25139-2011/04-R1]

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                                                  Circular No. 9198
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 C1 (McNAUGHT)
     Further to IAUC 9197, S. Nakano (Sumoto, Japan) reports that
images obtained by A. Asami and K. Nishiyama with the Bisei
Spaceguard Center's 1.0-m f/3 reflector on Feb. 12.8 UT show a coma
of diameter 16" but no tail.  All of the available astrometry, the
following preliminary parabolic orbital elements by G. V. Williams
(from 39 observations, Feb. 10-12), and an ephemeris appear on MPEC
2011-C79.

     T = 2011 Apr. 17.953 TT          Peri. =  84.440
                                      Node  = 192.460   2000.0
     q = 0.88341 AU                   Incl. =  16.831


2011 CQ_1
     A fast-moving minor planet discovered by R. A. Kowalski on
Catalina Sky Survey images taken with the 0.68-m Schmidt telescope
on Feb. 4.2 UT (cf. MPEC 2011-C12, 2011-C14) passed about 0.000079
AU from the earth on Feb. 4.82.  Having an absolute magnitude of H
approximately 32 (suggesting a diameter of 1-2 m), this is the
closest observed approach of an apparently natural object to the
earth, with the exception of 2008 TC_3, which impacted the earth on
2008 Oct. 6 (cf. IAUCs 8990, 8994).


COMETS C/2009 U13, C/2009 U14, C/2009 Y5-Y8 (SOHO)
     Further to IAUCs 9171 and 9186, additional near-sun comets
have been found on SOHO website images -- presumed Kreutz
sungrazers except for C/2009 Y8 (Meyer group), which was stellar in
appearance (peak mag about 7).  K. Battams notes that C/2009 U13
was stellar in appearance in C3 images, but slightly diffuse in C2
images.  C/2009 U14 was diffuse and quite bright with a tail.
C/2009 Y5, which was found by H. Tan (observer code 'HT'), peaked
near mag about 7.5.  C/2009 Y6, was also found by B. Zhou; it was
also stellar in appearance (peak mag about 7.5), as were C/2009 Y7
(peak mag about 7.5-8) and C/2009 Y8 (peak mag about 7).

 Comet        2009 UT       R.A.(2000)Decl.   Inst.  F    MPEC
 C/2009 U13   Oct. 29.084   14 05.5  -15 48   C3/2  BZ   2010-L85
 C/2009 U14        30.112   13 55.5  -16 36   C3/2  BZ   2010-L85
 C/2009 Y5    Dec. 16.729   17 42.5  -24 40   C2    HT   2010-M19
 C/2009 Y6         17.079   17 42.6  -25 08   C2    JR   2010-M19
 C/2009 Y7         17.579   17 45.2  -25 10   C2    ZX   2010-M19
 C/2009 Y8         17.729   17 41.6  -22 35   C2    ZX   2010-M19

                      (C) Copyright 2011 CBAT
2011 February 12               (9198)            Daniel W. E. Green