[Iaude] CBET 4578: 20181201 : COMET C/2018 V2 (ATLAS)

quai at eps.harvard.edu quai at eps.harvard.edu
Sat Dec 1 07:46:44 EST 2018

                                                  Electronic Telegram No. 4578
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau at eps.harvard.edu (alternate cbat at iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network

     An apparently asteroidal object discovered on Nov. 2 UT (discovery
observations tabulated below) with a 0.5-m f/2 Schmidt reflector at Mauna Loa,
Hawaii, in the course of the "Asteroid Terrestrial-impact Last Alert System"
(ATLAS) search program has been found to show cometary appearance by CCD
astrometrists elsewhere after it was posted on the Minor Planet Center's
PCCP webpage.

     2018 UT             R.A. (2000) Decl.       Mag.
     Nov.  2.52670    3 30 49.17   - 7 31 48.5   19.1
           2.53671    3 30 46.19   - 7 31 57.6   19.0
           2.54109    3 30 45.09   - 7 32 02.6   19.1
           2.54679    3 30 43.59   - 7 32 08.1   19.1

K. Sarneczky and A. Ordasi, Konkoly Observatory, report that fifteen stacked
60-s unfiltered CCD images taken with the 0.60-m Schmidt telescope at
Piszkesteto Station of Konkoly Observatory on Nov. 5.9 UT show a starlike
nuclear condensation and a very faint, coma 5" in diameter and asymmetric
toward the north.  R. Weryk notes that two w-band exposures taken on Nov. 6.5
with the Pan-STARRS2 1.8-m Ritchey-Chretien reflector at Haleakala show that
this object appears to be a comet, with a full-width-at-half-maximum of
about 1".8 measured perpendicular to its direction of motion, which is larger
than the neighboring stars (FWHM = 1".22); there also appears to be a short
tail towards the north, which is not in the direction of motion.
R. A. Mastaler found a diffuse tail approximately 10" long in p.a. about
60 degrees in images taken on Nov. 13.3 in poor (3".0) seeing conditions with
the Spacewatch 0.9-m f/3 reflector at Kitt Peak, providing red magnitude
19.1-19.3; his follow-up observations the following night (Nov. 14.3) in
2".4 seeing also showed the diffuse tail (mag 19.0-19.5).  T. H. Bressi
measured a 7" tail in p.a. 45 degrees in images obtained in bright moonlight
with the Spacewatch 1.8-m f/2.7 reflector at Kitt Peak on Nov. 25.3.
     The available astrometry (including pre-discovery observations made with
the Pan-STARRS2 1.8-m telescope at Haleakala on Oct. 18, when the magnitude
was given as 19.6-20.2), the following preliminary elliptical orbital elements
by G. V. Williams (from 146 observations spanning Oct. 18-Nov. 29), and an
ephemeris appear on MPEC 2018-X10.

                    Epoch = 2018 Nov. 18.0 TT
     T = 2018 Nov. 26.9781 TT         Peri. = 318.6592
     e = 0.903614                     Node  = 356.7871  2000.0
     q = 2.474982 AU                  Incl. = 159.1110
       a = 25.677716 AU    n = 0.0075748    P = 130.1 years

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

                         (C) Copyright 2018 CBAT
2018 December 1                  (CBET 4578)              Daniel W. E. Green

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