Electronic Telegram No. 4029 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@eps.harvard.edu (alternate cbat@iau.org) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network COMET C/2014 W9 (PANSTARRS) L. Denneau and R. Wainscoat report the discovery of another comet in three w-band CCD exposures taken with the 1.8-m Pan-STARRS1 telescope at Haleakala on Nov. 22 (discovery observations tabulated below), the object showing a non-stellar appearance with what appears to be a broad, very-low- surface-brightness coma. 2014 UT R.A. (2000) Decl. Mag. Nov. 22.63535 11 33 48.45 +12 43 52.3 20.5 22.63930 11 33 49.01 +12 43 48.7 20.5 22.64324 11 33 49.57 +12 43 45.0 20.2 M. Micheli and Wainscoat write that three follow-up 60-s CCD exposures taken by queue observer D. Woodworth at the 3.6-m Canada-France-Hawaii Telescope atop Mauna Kea on Nov. 23.6 UT show subtle hints of cometary appearance (coma slightly soft with FWHM about 0".9 in 0".8 seeing) with a possible tail to the northwest; the red magnitude was given as 19.4-20.2. Wainscoat and Micheli obtained three additional 180-s exposures at the CFHT (queue observer Woodworth) on Nov. 25.6, noting a similar appearance (a nearly stellar coma), with the apparent tail to the northwest being enhanced by the longer exposure time. After the object was posted on the Minor Planet Center's PCCP webpage H.Sato, Tokyo, Japan, obtained twelve stacked 60-s exposures with an iTelescope 0.51-m f/6.8 astrograph (+ luminance filter) near Mayhill, NM, USA, on Nov. 23.5 to find w-band magnitude 19.6, with a moderately condensed but asymmetrical coma 8" in diameter. The available astrometry (including pre-discovery observations from Oct. 25.5 UT obtained at Mount Lemmon by E. J. Christensen), the following preliminary parabolic orbital elements by G. V. Williams, and an ephemeris appear on MPEC 2014-W118. T = 2015 Feb. 9.4306 TT Peri. = 162.5888 Node = 23.0158 2000.0 q = 1.652134 AU Incl. = 10.5658 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2014 CBAT 2014 November 27 (CBET 4029) Daniel W. E. Green