[IAUC] IAUC 9035: C/2009 F6; 2009 DD_47 [25139-2009/08-R1]

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                                                  Circular No. 9035
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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COMET C/2009 F6 (YI-SWAN)
     Further to IAUC 9034, H. Yamaoka, Kyushu University, informs
the Central Bureau that he received an e-mailed report on March 28
of the discovery by Dae-am Yi (Yeongwol-kun, Gangwon-do, Korea) of
a possible comet with a noticeable greenish coma of diameter about
1' (discovery observation tabulated below) on two 60-s CCD
exposures taken about 80 seconds apart with a Canon 5D camera and a
90-mm f/2.8 camera lens.  Orbital calculations suggest that this
object is identical with C/2009 F6.

     2009 UT            R.A. (2000) Decl.       Mag.     Observer
     Mar. 26.835      22 39 40     +49 49 08    12.5     Yi

The available precise astrometry, the following preliminary
parabolic orbital elements from the precise astrometry only, and an
ephemeris appear on MPEC 2009-G21.

     T = 2009 May   8.056 TT          Peri. = 130.432
                                      Node  = 278.927   2000.0
     q = 1.26991 AU                   Incl. =  85.724

     Further visual total-magnitude and coma-diameter estimates:
Apr. 6.16 UT, 8.1, 7' (J. J. Gonzalez, Burgos, Spain, 25x100
binoculars); 6.91, 9.7, 2' (V. Nevski, Vitebsk, Belarus, 0.30-m
reflector); 7.06, 8.5, 4' (B. H. Granslo, Fjellhamar, Norway,
0.20-m reflector; moonlight); 7.09, 8.5, 4' (M. Reszelski,
Szamotuly-Galowo, Poland, 15x70 binoculars).
     S. Korotkiy and T. Kryachko, Moscow, report that their
unfiltered CCD observations with a 30-cm telescope at Karachay-
Cherkessia, Russia, on Apr. 7.06 show a bright asymmetrical coma of
size 332" x 354" (major axis in p.a. 161 deg) with an asymmetrical
condensation of size 12".8 x 19".3 (major axis in p.a. 320 deg).


2009 DD_47
     Numerous attempts to find cometary appearance in the
retrograde-orbiting object 2009 DD_47 (cf. MPEC 2009-E12; T = 2008
Oct. 29.6206 TT, e = 0.976539, q = 2.242187 AU, Peri. = 315.1224
deg, Node = 173.8329 deg, i = 107.8501 deg, equinox 2000.0) have
produced negative results.  J. Young, Table Mountain Observatory,
writes that observations taken on numerous nights in March by M.
Hicks, H. Rhoades, and himself show only a starlike appearance.

                      (C) Copyright 2009 CBAT
2009 April 7                   (9035)            Daniel W. E. Green