Electronic Telegram No. 4023 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 W5 (LEMMON-PANSTARRS) R. J. Wainscoat and R. Weryk report the discovery of yet another comet in four w-band CCD exposures taken with the 1.8-m Pan-STARRS1 telescope at Haleakala on Nov. 20; the object has a slightly diffuse appearance, and there is a faint tail extending for approximately 5" towards p.a. approximately 30 degrees in each images. The object was also discovered on two nights (Nov. 16 and 17) by the Mount Lemmon Survey (observer A. D. Grauer) as apparently asteroidal (reported as a near-earth object but did not score high enough to be posted automatically on the Minor Planet Center's NEOCP webpage). The discovery observations are tabulated below. 2014 UT R.A. (2000) Decl. Mag. Observer Nov. 16.29308 3 58 46.07 +15 21 15.9 19.7 Grauer 16.29765 3 58 45.76 +15 21 14.0 20.1 " 16.30222 3 58 45.45 +15 21 12.4 19.8 " 17.38727 3 57 23.25 +15 12 59.2 20.3 " 17.39262 3 57 22.89 +15 12 57.5 19.9 " 17.39797 3 57 22.39 +15 12 54.3 20.4 " 17.40335 3 57 22.02 +15 12 52.2 19.9 " 20.47976 3 53 26.93 +14 49 19.3 21.4 Pan-STARRS1 20.49097 3 53 26.06 +14 49 14.2 21.6 " 20.50219 3 53 25.20 +14 49 09.0 21.3 " 20.51339 3 53 24.32 +14 49 03.8 21.3 " Wainscoat and M. Micheli report that three 60-s r-band follow-up exposures, tracked at the rate of the comet by Wainscoat and D. Woodworth with the 3.6-m Canada-France-Hawaii Telescope at Mauna Kea on Nov. 21.34 UT, show the object as having a slightly diffuse appearance, and a tail extending for approximately 7" toward p.a. approximately 40 degrees. After the object was posted on the Minor Planet Center's PCCP webpage, other CCD astrometrists have also commented on the object's cometary appearance. W. H. Ryan (Magdalena Ridge Observatory 2.4-m f/8.9 reflector + R-band filter) notes a tail in p.a. about 45 deg (and gives the magnitude as 20.3-20.4) on images obtained on Nov. 21.3 UT. J. V. Scotti, Lunar and Planetary Laboratory, University of Arizona, writes that images taken with the Spacewatch 1.8-m telescope at Kitt Peak on Nov. 21.4 show a coma of diameter 5" and red mag 19.0, with a tail extending 0'.4 in p.a. 41 deg. H. Sato, Tokyo, Japan, writes that sixteen stacked 60-s exposures taken with an iTelescope 0.51-m f/6.8 astrograph (+ luminance filter) at Siding Spring on Nov. 21.6 shows the comet to be moderately condensed with a coma 8" in diameter and no tail; the w-band magnitude was 19.6 as measured within a circular aperture of radius 6".6. The available astrometry, the following preliminary parabolic orbital elements by G. V. Williams, and an ephemeris appear on MPEC 2014-W68. T = 2016 Feb. 11.3558 TT Peri. = 277.2202 Node = 245.5431 2000.0 q = 2.579417 AU Incl. = 146.2761 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2014 CBAT 2014 November 22 (CBET 4023) Daniel W. E. Green