[IAUC] IAUC 9071: C/2009 R1; NEPTUNE I (TRITON) [XXXXX-XXXX/XX-F1]

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                                                  Circular No. 9071
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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COMET C/2009 R1 (McNAUGHT)
     R. H. McNaught reports his discovery of a comet with a
circular 12" comet on CCD images taken with the 0.5-m Uppsala
Schmidt telescope at Siding Spring (discovery observation tabulated
below), with follow-up images on the same night showing the object
to be clearly diffuse.  Pre-discovery Uppsala Schmidt images taken
by G. J. Garradd and McNaught on July 20, Aug. 1, and 18 have been
identified by T. Spahr and B. G. Marsden in astrometry submitted to
the Minor Planet Center (McNaught now reporting only marginal coma
visible on those dates).  Following posting on the MPC's 'NEOCP'
webpage, other CCD astrometrists have noted the object's cometary
appearance.  M. Busch, R. Kresken, J. Kuusela, and Z. Sodnik
(European Space Agency's Optical Ground Station, Tenerife, 1.0-m
f/4.4 reflector, Sept. 9.9 UT) measure a coma of size 6"-8".  E.
Guido and G. Sostero write that twenty co-added 120-s unfiltered
exposures (obtained remotely on Sept. 10.2 with a 0.25-m reflector
near Mayhill, NM, U.S.A.) show a coma of diameter about 12" with a
hint of elongation toward p.a. 65 deg.

     2009 UT             R.A. (2000) Decl.       Mag.   Observer
     Sept. 9.61721   21 19 28.81   -33 47 55.2   17.3   McNaught

The available astrometry, the following parabolic orbital elements
by B. G. Marsden, and an ephemeris appear on MPEC 2009-R33.

     T = 2010 July  2.1701 TT         Peri. = 130.8635
                                      Node  = 322.7253  2000.0
     q = 0.401431 AU                  Incl. =  76.7005


NEPTUNE I (TRITON)
     E. Lellouch, C. de Bergh, and B. Sicardy, Observatoire de
Paris; and H.-U. Kaeufl, European Southern Observatory (ESO),
report that they observed Triton on July 4 with the CRIRES
spectrometer on the Very Large Telescope (UT1) at ESO.  Focussing
on the bandpass 2.32-2.37 microns (spectral resolution 60000),
they detected at least four lines [R(3), R(4), P(2), and P(5)] of
the CO(2-0) band.  In addition, the observed spectral range shows
about ten lines due to gaseous methane.  These observations
represent the first detection of CO in Triton's atmosphere, as well
as the only observation of methane gas since its detection in the
ultraviolet by Voyager in 1989.

                      (C) Copyright 2009 CBAT
2009 September 10              (9071)            Daniel W. E. Green