[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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