[Iaude] CBET 4797: COMET P/2020 K9

quai at eps.harvard.edu quai at eps.harvard.edu
Thu Jun 18 16:11:36 EDT 2020


                                                  Electronic Telegram No. 4797
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


COMET P/2020 K9 (LEMMON-PANSTARRS)
     An apparently asteroidal object reported on single nights fromo CCD
images obtained with both the 1.5-m reflector of the Mt. Lemmon Survey (on
May 22) and with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala
(on May 26), and linked by G. V. Williams with other incidental astrometry
received by the Minor Planet Center and posted on the MPC's PCCP webpage
after William's linkage on June 16 due to its comet-like orbit, has been
found to show cometary appearance on images taken with other telescopes.  The
discovery astrometry is tabulated below.

     2020 UT             R.A. (2000) Decl.       Mag.   Observer
     May  22.43234   21 34 47.09   + 2 38 13.0   20.5   Mt. Lemmon
          22.43752   21 34 47.26   + 2 38 14.3   20.6     "
          22.44269   21 34 47.45   + 2 38 15.8   20.7     "
          22.44788   21 34 47.63   + 2 38 17.0   20.7     "
          26.58036   21 37 12.94   + 2 54 17.9   19.5   Pan-STARRS1
          26.59479   21 37 13.41   + 2 54 21.1   19.6     "
          26.60203   21 37 13.64   + 2 54 22.7   19.5     "

H. Sato, Tokyo, Japan, reports that twelve stacked 60-s exposures taken
remotely on June 16.74 UT with a 0.51-m f/6.8 astrograph at Siding Spring,
NSW, show a strongly condensed, asymmetrical coma 8" in diameter and no tail;
the magnitude was 19.4 as measured within a circular aperture of radius 4".9.
R. Weryk, University of Hawaii, writes that three 60-s gri-band images taken
by R. Wainscoat, C. Wipper, and T. Burdullis with the 3.6-m Canada-France-
Hawaii Telescope at Mauna Kea on June 17.5 show that this object is clearly
a comet, with a broad tail about 5" long in p.a. 230-280 degrees; the coma
was larger than nearby stars (full-width-at-half-maximum 1".83, vs. 0".93).
     The available astrometry appear on MPEC 2020-M26.  The following
parabolic orbital elements by S. Nakano, Sumoto, Japan, are from 22
observations spanning 2020 May 22-June 18 (mean residual 0".3) and indicate
that the comet passed 0.06 AU from Jupiter in 2016 April.

                    Epoch = 2021 Jan. 26.0 TT
     T = 2021 Feb. 12.78790 TT        Peri. = 197.17626
     e = 0.3220120                    Node  = 166.21846 2000.0
     q = 2.8456437 AU                 Incl. =  23.21800
       a =  4.1971886 AU   n = 0.11462157   P =   8.60 years

The following ephemeris by the undersigned from the above orbital elements
uses photometric power-law parameters H = 12.0 and 2.5n = 10 for the
magnitudes.

Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase  Mag.
2020 04 21    21 09.53   +00 06.6    3.459    3.290    71.9    16.9  19.9
2020 04 26    21 14.25   +00 32.9    3.383    3.277    75.4    17.3  19.8
2020 05 01    21 18.73   +00 58.7    3.306    3.264    78.8    17.6  19.7
2020 05 06    21 22.95   +01 23.8    3.228    3.252    82.4    17.9  19.7
2020 05 11    21 26.90   +01 47.9    3.150    3.239    86.0    18.1  19.6
2020 05 16    21 30.55   +02 10.9    3.072    3.227    89.6    18.3  19.5
2020 05 21    21 33.89   +02 32.4    2.993    3.215    93.3    18.3  19.5
2020 05 26    21 36.89   +02 52.1    2.915    3.203    97.1    18.3  19.4
2020 05 31    21 39.53   +03 09.8    2.838    3.191   101.0    18.2  19.3
2020 06 05    21 41.80   +03 25.1    2.762    3.179   105.0    18.0  19.2
2020 06 10    21 43.68   +03 37.8    2.687    3.167   109.0    17.6  19.2
2020 06 15    21 45.15   +03 47.3    2.615    3.156   113.2    17.2  19.1
2020 06 20    21 46.19   +03 53.5    2.544    3.144   117.4    16.7  19.0
2020 06 25    21 46.79   +03 55.8    2.476    3.133   121.8    16.0  18.9
2020 06 30    21 46.94   +03 54.0    2.411    3.122   126.3    15.2  18.9
2020 07 05    21 46.64   +03 47.7    2.349    3.111   130.9    14.3  18.8
2020 07 10    21 45.90   +03 36.6    2.292    3.100   135.5    13.3  18.7
2020 07 15    21 44.73   +03 20.5    2.239    3.090   140.3    12.1  18.6
2020 07 20    21 43.15   +02 59.1    2.191    3.079   145.1    10.9  18.6
2020 07 25    21 41.19   +02 32.4    2.148    3.069   149.8     9.6  18.5
2020 07 30    21 38.91   +02 00.5    2.111    3.059   154.5     8.2  18.5
2020 08 04    21 36.38   +01 23.6    2.080    3.049   159.0     6.9  18.4
2020 08 09    21 33.65   +00 41.9    2.056    3.039   162.9     5.6  18.4
2020 08 14    21 30.80   -00 03.9    2.038    3.030   165.7     4.8  18.4
2020 08 19    21 27.93   -00 53.3    2.027    3.020   166.5     4.5  18.3
2020 08 24    21 25.12   -01 45.5    2.023    3.011   165.0     5.0  18.3
2020 08 29    21 22.47   -02 39.6    2.026    3.002   161.8     6.0  18.3
2020 09 03    21 20.06   -03 34.8    2.036    2.994   157.6     7.4  18.3
2020 09 08    21 17.97   -04 30.0    2.053    2.985   152.9     8.8  18.3
2020 09 13    21 16.26   -05 24.6    2.075    2.977   148.0    10.3  18.3
2020 09 18    21 14.99   -06 17.7    2.104    2.969   142.9    11.8  18.3
2020 09 23    21 14.22   -07 08.5    2.139    2.961   137.9    13.1  18.4
2020 09 28    21 13.97   -07 56.6    2.178    2.953   132.9    14.4  18.4


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

                         (C) Copyright 2020 CBAT
2020 June 18                     (CBET 4797)              Daniel W. E. Green



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