Electronic Telegram No. 4290
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau@eps.harvard.edu (alternate cbat@iau.org)
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Prepared using the Tamkin Foundation Computer Network


COMET P/2016 N3 = P/2007 R3 (GIBBS)
     A comet found on Catalina Sky Survey images taken by D. C. Fuls on July
15.45-15.46 UT with the 0.68-m Schmidt telescope (discovery observations
tabulated below), and subsequently posted on the Minor Planet Center's NEOCP
and PCCP webpages, has been found to be the first observed return of comet
P/2007 R3 (cf. IAUC 8869).  Fuls reported a faint coma 10' [sic] across with
a tail extending approximately 12' [sic] in p.a. 270 deg.

     2016 UT             R.A. (2000) Decl.       Mag.   Observer
     July 15.44554    1 18 26.76   + 5 46 13.7   17.8   Fuls
          15.45759    1 18 27.53   + 5 46 18.8   17.9     "

Other CCD astrometrists have also noted the cometary appearance of this
object.  A. Novichonok, Petrozavodsk State University, Petrozavodsk, Russia,
writes that unfiltered 120-s images obtained by G. Borisov with a 0.5-m f/2
astrograph at the MARGO Observatory in Crimea on July 16.96 UT show a diffuse,
moderately condensed coma with diameter 15" and total mag 17.8 inside a 0'.33
square aperture; there is a possible tail with length around 0'.3 in p.a. 260
deg.  L. Buzzi, Varese, Italy, notes that stacked images obtained with a
0.60-m f/4.64 reflector on July 17.1 show a compact coma 7" wide that is
elongated in p.a. around 250 deg.  H. Sato, Tokyo, Japan, reports that ten
stacked 60-s exposures taken with an iTelescope 0.43-m f/6.8 astrograph (+
luminance filter) at Nerpio, Spain, shows a strongly condensed coma 8" in
diameter with no tail; the w-band magnitude was 18.1 as measured within a
circular aperture of radius 5".0.
     The indicated correction to the orbit for P/2007 N3 by G. V. Williams on
MPEC 2013-B90 is Delta(T) = -0.48 day.  Additional astrometry, the following
linked orbital elements by Williams (from 126 observations 2007 Sept. 10-2016
July 17; mean residual 0".6), and an ephemeris appear on MPEC 2016-O265.

                    Epoch = 2016 May  12.0 TT
     T = 2016 May  26.92419 TT        Peri. = 312.21325
     e = 0.4138286                    Node  =  30.07233 2000.0
     q = 2.5208054 AU                 Incl. =   3.79256
       a =  4.3004580 AU   n = 0.11051774   P =   8.92 years


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

                         (C) Copyright 2016 CBAT
2016 July 18                     (CBET 4290)              Daniel W. E. Green