[IAUC] IAUC 9103: P/2009 Y2; eta Car [25139-2010/01-R1]

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                                                  Circular No. 9103
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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COMET P/2009 Y2 (KOWALSKI)
     As first announced on CBET 2088, R. A. Kowalski (Lunar and
Planetary Laboratory) reports a cometary object (discovery
observation tabulated below) found on images taken with the
Catalina Sky Survey's 0.68-m Schmidt telescope; in good seeing, it
appeared more diffuse than a typical object of comparable
brightness and showed what appeared to be a round coma with strong
condensation in p.a. 270 deg.  Observations by A. R. Gibbs with the
Mt. Lemmon 1.5-m reflector on Dec. 20.2 UT showed a 4".5 broad tail
in p.a. 45 deg.  After the discovery had been added to the Minor
Planet Center's 'NEO Confirmation Page', W. H. Ryan and E. V. Ryan
(Magdalena Ridge Observatory, 2.4-m f/8.9 reflector) on Dec. 20.2
and 21.1 confirmed a faint tail in p.a. 45 deg.  A 105-min
integration by P. Birtwhistle (Great Shefford, Berkshire, England,
0.40-m f/6 Schmidt-Cassegrain reflector) on Dec. 20.9 showed the
object to have a diameter of about 6" with a 10" extension in p.a.
50 deg; a faint, straight tail was suspected, also in p.a. 50 deg,
at least 25" (and possibly up to 45") long.

     2009 UT             R.A. (2000) Decl.       Mag.   Observer
     Dec. 20.11774   00 37 55.48   +31 27 27.2   18.9   Kowalski

The initial astrometry, along with preliminary parabolic orbital
elements, appeared on MPEC 2009-Y40.  Additional astrometry has led
to the computation of the following elliptical elements (from MPC
67973):

     T = 2010 Mar. 30.696 TT          Peri. = 171.805
     e = 0.62349                      Node  = 262.256   2000.0
     q = 2.33726 AU                   Incl. =  29.864
       a =  6.20772 AU     n = 0.063724     P =  15.47 years


eta CARINAE
     A. Verveer, Perth Observatory; and D. Frew, Macquarie
University, report the following B and V photometry of eta Car
obtained with a 40-cm f/11 reflector (+ Apogee AP7 CCD camera,
using standard Bessell filters; comparison star HDE 303308) at
Perth Observatory:  June 5.526 UT, V = 4.72, B-V = +0.71; Nov.
20.7914, 4.665, +0.709; 21.7733, 4.655, +0.714; 25.7814, 4.665,
0.714.  The photometry was summed through a 22" aperture and
naturally includes the central binary star plus all of the
surrounding Homunculus nebula; the recent HST photometry of
Davidson et al. (IAUC 9094) refers only to the star itself and is
about a half magnitude fainter.

                      (C) Copyright 2009 CBAT
2009 December 31               (9103)            Daniel W. E. Green