[IAUC] CBET 3258: 20121018 : COMET C/2012 T5 (BRESSI)

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                                                  Electronic Telegram No. 3258
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau en eps.harvard.edu (alternate cbat en iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


COMET C/2012 T5 (BRESSI)
     T. H. Bressi reports his discovery of a diffuse comet with an apparent
faint tail about 9" long in p.a. 260 degrees on CCD mosaic images taken
with the Spacewatch 0.9-m f/3 reflector at Kitt Peak (discovery observations
tabulated below); follow-up observations by Bressi with the Spacewatch 1.8-m
f/2.7 reflector on Oct. 16.3 UT show the comet to be diffuse with a broad tail
extending about 10" in p.a. about 27 deg.  After posting on the Minor Planet
Center's NEOCP webpage, other CCD astrometrists have also reported on the
object's cometary appearance.  Images taken by P. Ruiz (1.0-m f/4.4 reflector
at the European Spage Agency's Optical Ground Station, Tenerife; Oct. 16.0;
measured by A. Kn\"ofel, D. Koschny, and M. Busch) show the small tail.
William H. Ryan (Magdalena Ridge Observatory, 2.4-m f/8.9 reflector; Oct.
16.3) notes a distinct coma and a tail in p.a. about 270 deg in R-band images.
G. Hug (Scranton, KS, U.S.A.; 0.56-m reflector; Oct. 16.3) found a short,
broad tail in p.a. about 290 deg.  Fifteen stacked 60-s exposures taken by
R. Holmes (Ashmore, IL, USA; 0.61-m f/4 astrograph; measured by L. Buzzi, H.
Devore, S. Foglia, and T. Vorobjov; Oct. 16.4) show a coma 15" x 10" in size,
elongated in p.a. 280 deg, and a wide tail 45" long in p.a. 275 degrees.
E. Bryssinck (Kruibeke, Belgium; 0.4-m f/3.8 astrograph; Oct. 16.9) writes
that nine stacked, unfiltered images reveal a coma of size 12" x 16",
elongated toward p.a. about 285 deg, with a very faint tail extending for
approximately 18" in p.a. 273 degrees.  L. Buzzi (Varese, Italy; 0.38-m f/6.8
reflector; Oct. 17.0) reports that a stack of images totalling 39 minutes of
exposure time in good seeing (but with passing high clouds) shows a diffuse
coma 10" wide, with a fan-shaped tail 15" long in p.a. about 275 deg.  Images
obtained by G. Masi and F. Nocentini (Ceccano, Italy; 0.36-m f/8.7 reflector;
measured by G. Masi and U. Masi; Oct. 17.0) show a coma at least 10" in size.
R. Ligustri (Udine, Italy; remotely using a 0.25-m f/3.3 reflector at the RAS
Observatory near Mayhill, NM, U.S.A.; Oct. 17.5) finds that ten 120-s stacked
images show a diffuse coma and a 30" tail toward p.a. 260 deg.  H. Sato
(Tokyo, Japan; remotely using a 0.51-m f/6.8 astrograph at the RAS
Observatory near Mayhill, NM, U.S.A.; Oct. 17.5) finds a moderately condensed
coma of diameter 23" (with V-band magnitude 17.7 measured within a circular
aperture of radius 11".5) and a 30" tail toward p.a. 280 degrees.  Seven
stacked 120-s R-band images taken remotely by E. Guido, G. Sostero, and N.
Howes with a 0.43-m f/6.8 astrograph at the RAS Observatory (ITelescope
network) near Mayhill, NM, U.S.A. on Oct. 18.33 shows a compact coma about
5" in diameter (mag 17.9-18.2) and a tail nearly 12" long in p.a. 270 deg.

     2012 UT             R.A. (2000) Decl.       Mag.   Observer
     Oct. 14.41919    4 17 29.19   +21 57 27.1   18.6   Bressi
          14.43695    4 17 28.43   +21 57 15.7   18.4     "
          14.45466    4 17 27.47   +21 57 02.1   18.6     "

The available astrometry, the following preliminary parabolic orbital
elements by Gareth V. Williams, and an ephemeris appear on MPEC 2012-U38.

     T = 2013 Feb. 23.5584 TT         Peri. = 318.2738
                                      Node  = 230.5578  2000.0
     q = 0.319891 AU                  Incl. =  71.8724


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2012 CBAT
2012 October 18                  (CBET 3258)              Daniel W. E. Green