Electronic Telegram No. 4082
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/2015 F1 (PANSTARRS)
     R. Weryk and R. Wainscoat, Institute for Astronomy, University of Hawaii,
report the discovery of another apparent comet in four w-band exposures taken
with the 1.8-m Pan-STARRS1 telescope at Haleakala on Mar. 21.6 UT (discovery
observations tabulated below); the object shows a tail extending for at least
5" towards position angle approximately 285 degrees (the object is located
close to an image defect that makes precise morphology measurements, including
tail length, difficult).

     2015 UT             R.A. (2000) Decl.       Mag.
     Mar. 21.58025   16 37 43.57   -22 38 43.2   19.1
          21.59087   16 37 44.00   -22 38 44.7   19.0
          21.60151   16 37 44.42   -22 38 46.4   19.0
          21.61215   16 37 44.85   -22 38 48.1   18.8

Five 60-s follow-up CCD images obtained by Wainscoat and M. Micheli using the
3.6-m Canada-France-Hawaii Telescope (queue observer P. Forshay) on Mar. 22.6
UT show the object to be clearly cometary, displaying a bright and thin tail
at least 1' long toward p.a. 280 deg; the red magnitude was measured as 19.0-
19.2.  After the comet was posted on the Minor Planet Center's PCCP webpage,
W. H. Ryan obtained R-band images with the Magdalena Ridge Observatory 2.4-m
f/8.9 reflector on Mar. 22.44-22.47 that yield magnitude 17.7 and showing a
prominent tail in p.a. about 280 deg.

     The available astrometry, the following preliminary elliptical orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2015-F119.

     T = 2015 Jan. 24.7330 TT         Peri. = 173.1194
     e = 0.428308                     Node  =  40.7475  2000.0
     q = 2.559488 AU                  Incl. =   2.7913
       a =  4.477043 AU    n = 0.1040440    P =   9.47 years


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2015 CBAT
2015 March 27                    (CBET 4082)              Daniel W. E. Green