Electronic Telegram No. 3987 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 P/2014 R5 (LEMMON-PANSTARRS) B. Bolin and L. Denneau suspect the discovery of a comet in three w-band CCD exposures taken on Sept. 19 with the Pan-STARRS1 1.8-m Ritchey-Chretien telescope at Haleakala, Maui, Hawaii (discovery observations tabulated below). The object has a distinctly non-stellar appearance, larger than stars of similar brightness and with a broad, low-surface-brightness tail extending approximately" in p.a. approximately 240 degrees. R. Wainscoat obtained three 60-s follow-up exposures using the Canada-France-Hawaii Telescope on Sept. 21 UT (queue observer A. Draginda); the comet showed a broad, low-surface- brightness tail extending for approximately 5" in p.a. approximately 250 deg. T. Spahr linked the Pan-STARRS1 observations to astrometry reported by J. A. Johnson of an apparently asteroidal object found via the Mt. Lemmon Survey on Sept. 14.4. 2014 UT R.A. (2000) Decl. Mag. Observer Sept.14.39233 1 12 02.39 + 5 58 14.2 19.1 Johnson 14.39940 1 12 02.19 + 5 58 12.7 18.7 " 14.40647 1 12 02.01 + 5 58 11.9 18.9 " 19.47296 1 09 42.93 + 5 41 16.0 20.5 Pan-STARRS 19.47363 1 09 42.90 + 5 41 15.8 20.3 " 19.48535 1 09 42.53 + 5 41 13.4 20.3 " 19.48602 1 09 42.51 + 5 41 13.1 20.3 " 19.49778 1 09 42.12 + 5 41 10.6 20.3 " 19.49845 1 09 42.10 + 5 41 10.5 20.4 " After the object was posted on the Minor Planet Center's PCCP webpage, other CCD astrometrists have commented on the object's cometary appearance. H. Sato (Tokyo, Japan) used 120 stacked 60-s exposures obtained on Sept. 20.65-20.66 with an iTelescope 0.51-m f/6.8 astrograph (+ luminance filter) at Siding Spring to discern a strongly condensed coma 10" in diameter (with w-band magnitude 18.8 as measured within a circular aperture of radius 6".5) and a hint of tail 20" long toward p.a. 240 degrees. S. Gajdos and P. Veres stacked images taken with a 0.6-m f/5.5 reflector at Modra, Slovakia, on Sept. 21.05- 21.07 to find the comet slightly diffuse with a short tail fan in p.a. 240-260 deg. The available astrometry (including pre-discovery observations from Pan-STARRS1 on Sept. 7.5 reported today), the following preliminary elliptical orbital elements by G. V. Williams, and an ephemeris appear on MPEC 2014-S81. Epoch = 2014 July 2.0 TT T = 2014 June 19.9975 TT Peri. = 214.9060 e = 0.405351 Node = 126.5199 2000.0 q = 2.398741 AU Incl. = 1.0894 a = 4.033879 AU n = 0.1216521 P = 8.10 years NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2014 CBAT 2014 September 24 (CBET 3987) Daniel W. E. Green