[IAUC] IAUC 9170: COMET C/2010 S1 (LINEAR); C/2009 T11-T13, C/2009 U7-U9 [25139-2011/04-R1]

Mie Sep 14 16:19:45 ART 2011

                                                  Circular No. 9170
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/2010 S1 (LINEAR)
     An apparently asteroidal object discovered by the LINEAR
survey (discovery observation tabulated below), and posted on the
Minor Planet Center's 'NEOCP' webpage, has been found to show
cometary appearance by other CCD astrometrists.  D. Mayes (Table
Mountain Observatory, 0.6-m f/16 Cassegrain reflector) writes that
images taken on Sept. 23.4 UT show a bright coma with a small tail.
W. H. Ryan (Magdalena Ridge Observatory, 2.4-m reflector) reports
that R-band images obtained on Sept. 24.3 yield mag 17.5-17.7 and
show a point-spread function for the comet that is significantly
greater than that for field stars.  Eighteen stacked 120-s images
taken remotely by E. Guido and G. Sostero with a 0.25-m f/3.4
located at the GRAS Observatory (near Mayhill, NM, U.S.A.) on Sept.
24.3 show that this object appears soft compared to nearby field
stars of similar brightness with a slight elongation in the east-
west direction.

     2010 UT             R.A. (2000) Decl.       Mag.   Observer
     Sept.21.36090    3 40 52.37   +59 52 18.5   18.4   LINEAR

The available astrometry, the following very preliminary parabolic
orbital elements by B. G. Marsden, and an ephemeris appear on MPEC
2010-S41.

     T = 2013 May   9.420 TT          Peri. = 137.160
                                      Node  =  95.219   2000.0
     q = 4.40915 AU                   Incl. = 126.891

COMETS C/2009 T11-T13 AND C/2009 U7-U9 (SOHO)
     Further to IAUC 9168, additional near-sun comets have been
found on SOHO website images -- all presumed Kreutz sungrazers
except for C/2009 U7 (Meyer group).  C/2009 T11, C/2009 T12, and
C/2009 T13 all peaked near mag about 7.5 (the latter two described
as being diffuse).  C/2009 U7 (mag about 7.5-8) and C/2009 U9 (mag
about 7-7.5) were stellar in appearance.  C/2009 U8 peaked at mag
about 8.5.

 Comet        2009 UT       R.A.(2000)Decl.   Inst.  F    MPEC
 C/2009 T11   Oct. 14.071   13 05.1  - 9 20   C3/2  BZ   2010-L44
 C/2009 T12        14.096   13 02.5  - 9 27   C3/2  SY   2010-L44
 C/2009 T13        15.346   13 08.5  - 9 58   C3/2  ZX   2010-L44
 C/2009 U7         17.814   13 26.9  - 7 52   C2    BZ   2010-L45
 C/2009 U8         18.329   13 28.8  -11 04   C2    ZX   2010-L45
 C/2009 U9         21.679   13 29.7  -12 43   C3/2  BZ   2010-L45

                      (C) Copyright 2010 CBAT
2010 September 24              (9170)            Daniel W. E. Green