2013c2 20130216 ebryssinck

CBET 3417: 20130217 : COMET C/2013 C2 (TENAGRA): An apparently asteroidal object reported by P. R. Holvorcem (working with M. Schwartz) from CCD images taken on Feb. 14 with a  0.41-m f/3.75 astrograph at Schwartz's Tenagra Observatory (near Nogales, AZ, U.S.A.; discovery observations tabulted below), and posted on the Minor Planet Center's NEOCP webpage, was found by various CCD astrometrists on subsequent dates (including by the discoverers) to show cometary appearance.  Twelve co-added 150-s unfiltered exposures taken by Holvorcem and Schwartz between Feb. 15.25 and15.28 UT with the Tenagra II 0.81-m telescope in good seeing (FWHM 2".6) show a central condensation about 6" in diameter with an extended, diffuse coma of diameter about 25"; their additional three 240-s co-added exposures taken between Feb. 17.34 and 17.39 with the Tenagra III 0.41-m astrograph show a coma with diameter of about 15" in average seeing (FWHM 3".5). ....

...  Erik Bryssinck (Kruibeke, Belgium; remotely using an iTelescope.net 0.43-m f/6.8 reflector + luminance filter near Mayhill; stacked images taken around Feb. 16.3) finds a circular 14" coma with a diffuse condensation at the center of the coma.  B. L. Stevens (Las Cruces, NM, U.S.A.; 0.3-m Schmidt-Cassegrain reflector; Feb. 17.3) measured a wide tail 18" long in p.a. 305 degrees.


The available astrometry, the following preliminary parabolic orbital elements by G. V. Williams, and an ephemeris appear on  MPEC 2013-D22 : COMET C/2013 C2 (TENAGRA)