[Iaude] CBET 4966: COMET C/2017 K2 (PANSTARRS)
quai at eps.harvard.edu
quai at eps.harvard.edu
Wed May 12 08:32:11 EDT 2021
Electronic Telegram No. 4966
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 C/2017 K2 (PANSTARRS)
Selected CCD total-magnitude and coma-diameter measurements for this
comet (cf. CBET 4393): 2017 June 16.96 UT, 18.5, 0'.2 (K. Yoshimoto, Yamaguchi,
Japan, remotely using a 0.43-m reflector at Nerpio, Spain); Sept. 30.50, 18.3,
-- (K. Kadota, Ageo, Japan, 0.25-m reflector); 2018 Jan. 12.82, 18.1, --
(Kadota); Apr. 18.73, 18.0, 0'.4 (Yoshimoto, Yamaguchi, 0.20-m reflector);
Aug. 17.54, 17.6, -- (Kadota); 2019 Feb. 2.74, 17.3, -- (Kadota); May 5.63,
16.9, -- (Kadota); Sept. 25.44, 16.4, -- (Kadota); 2020 Jan. 18.81, 16.2, --
(Kadota); Mar. 21.73, 15.8, -- (Kadota); May 14.33, 15.9, 0'.6 (C. S. Morris,
Fillmore, CA, U.S.A., 41-cm reflector); June 10.33, 15.7, 0'.8 (Morris);
28.91, 14.6, 0'.42 (T. Scarmato, Calabria, Italy, 25-cm reflector + R_c
filter); Aug. 2.51, 15.1, -- (Kadota); 13.22, 15.5, 0'.8 (Morris); 16.83,
15.2, 0'.42 (Scarmato); Sept. 3.22, 15.5, 0'.9 (Morris); 23.18, 15.4, 1'.1
(Morris); Oct. 11.45, 15.2, 0'.8 (Yoshimoto); 17.14, 15.3, 1'.0 (Morris);
24.47, 14.8, -- (Kadota); Nov. 11.10, 15.1, 1'.0 (Morris); 17.11, 15.2, 1'.2
(Morris); Dec. 6.37, 14.5, -- (Kadota); 2021 Feb. 3.84, 14.3, -- (Kadota);
9.77, 13.7, 1'.7 (K. Harikae, Chiba, Japan, 0.15-m reflector + digital
camera); 21.74, 14.1, 1'.4 (Harikae); Mar. 10.74, 14.5, 0'.9 (Harikae); 18.44,
13.7, 1'.2 (H. Sato, Tokyo, Japan, remotely with a 0.43-m astrograph near
Mayhill, NM, USA); 25.77, 13.7, -- (Kadota); Apr. 8.90, 14.5, 0'.9 (Scarmato);
18.68, 14.0, 1'.2 (Yoshimoto); May 1.65, 13.3, -- (Kadota).
Visual total-magnitude and coma-diameter estimates by W. Hasubick,
Buchloe, Germany, with a 44-cm reflector: 2020 July 12.90 UT, 14.5, 0'.3;
Sept. 12.91, 13.5, 0'.2.
Pre-discovery observations of this comet were identified as far back as
2013 May 12.6 UT at Mauna Kea, when the total magnitude was given as 21.4-22.1
(cf. MPC 105642). Selected pre-discovery Catalina Sky Survey magnitudes are
as follows (op.cit.): 2015 Nov. 23.1, 19.8; 2016 May 6.5, 19.9; July 11.3,
19.7; 2017 Mar. 22.5, 19.1; Apr. 7.5, 18.8; 16.5, 19.2; 26.4, 19.6; May 3.4,
19.5.
The following updated orbital elements by S. Nakano (CBAT) are from 4213
observations spanning 2013 May 12-2021 May 3 (mean residual 0".4); the
corresponding original and future values of 1/a are +0.000028 and +0.001121,
respectively. These elements indicate that the comet will pass 2.66 AU from
Jupiter on 2024 Oct. 15 and 7.88 AU from Uranus on 2029 Oct. 16 UT.
Epoch = 2022 Dec. 7.0 TT
T = 2022 Dec. 19.67178 TT Peri. = 236.19715
e = 1.0008506 Node = 88.23537 2000.0
q = 1.7969443 AU Incl. = 87.56309
The following ephemeris by the undersigned from the above orbital elements
uses photometric power-law parameters H = 3.0 and 2.5n = 8 for the
magnitudes, which well represent the reported total magnitudes from 2013
to date. This is intrinsically a fairly bright comet, with presumably a
relatively large nucleus.
Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag.
2021 04 16 18 26.34 +40 45.8 6.420 6.606 96.3 8.7 13.6
2021 04 26 18 23.34 +41 37.2 6.267 6.526 100.5 8.7 13.5
2021 05 06 18 18.85 +42 23.0 6.120 6.444 104.3 8.7 13.4
2021 05 16 18 12.89 +43 00.0 5.983 6.363 107.7 8.7 13.3
2021 05 26 18 05.61 +43 24.8 5.856 6.281 110.3 8.7 13.2
2021 06 05 17 57.26 +43 34.5 5.743 6.199 112.2 8.7 13.1
2021 06 15 17 48.16 +43 26.6 5.645 6.116 113.2 8.8 13.0
2021 06 25 17 38.76 +42 59.4 5.561 6.033 113.1 8.9 13.0
2021 07 05 17 29.53 +42 12.4 5.494 5.950 112.0 9.1 12.9
2021 07 15 17 20.91 +41 06.3 5.443 5.866 109.8 9.4 12.8
2021 07 25 17 13.29 +39 42.8 5.407 5.782 106.7 9.7 12.8
2021 08 04 17 06.96 +38 04.5 5.386 5.698 102.9 10.0 12.7
2021 08 14 17 02.10 +36 14.5 5.377 5.614 98.3 10.3 12.6
2021 08 24 16 58.80 +34 16.3 5.378 5.529 93.3 10.5 12.6
2021 09 03 16 57.03 +32 13.1 5.387 5.444 87.9 10.7 12.5
2021 09 13 16 56.75 +30 07.8 5.401 5.358 82.2 10.7 12.5
2021 09 23 16 57.86 +28 03.3 5.417 5.272 76.4 10.7 12.4
2021 10 03 17 00.24 +26 01.7 5.433 5.186 70.5 10.5 12.4
2021 10 13 17 03.76 +24 04.8 5.445 5.099 64.7 10.2 12.3
2021 10 23 17 08.29 +22 14.2 5.450 5.012 59.1 9.8 12.3
2021 11 02 17 13.69 +20 31.0 5.447 4.925 53.7 9.3 12.2
2021 11 12 17 19.85 +18 55.9 5.432 4.838 48.8 8.9 12.2
2021 11 22 17 26.63 +17 29.6 5.404 4.750 44.5 8.4 12.1
2021 12 02 17 33.91 +16 12.5 5.361 4.661 41.0 8.0 12.0
2021 12 12 17 41.57 +15 04.7 5.300 4.573 38.6 7.7 11.9
2021 12 22 17 49.50 +14 06.3 5.223 4.484 37.6 7.7 11.8
2022 01 01 17 57.57 +13 17.3 5.127 4.395 38.1 7.9 11.7
2022 01 11 18 05.67 +12 37.4 5.012 4.306 40.0 8.4 11.6
2022 01 21 18 13.67 +12 06.3 4.879 4.216 43.2 9.2 11.4
2022 01 31 18 21.43 +11 43.6 4.727 4.126 47.5 10.1 11.3
2022 02 10 18 28.81 +11 28.6 4.559 4.036 52.6 11.2 11.1
2022 02 20 18 35.67 +11 20.7 4.374 3.945 58.3 12.3 11.0
2022 03 02 18 41.83 +11 18.8 4.176 3.855 64.5 13.4 10.8
2022 03 12 18 47.10 +11 21.9 3.965 3.764 71.2 14.5 10.6
2022 03 22 18 51.26 +11 28.5 3.744 3.674 78.3 15.4 10.4
2022 04 01 18 54.06 +11 36.8 3.515 3.583 85.8 16.1 10.2
2022 04 11 18 55.19 +11 44.2 3.283 3.492 93.6 16.6 9.9
2022 04 21 18 54.34 +11 47.7 3.050 3.401 101.8 16.8 9.7
2022 05 01 18 51.11 +11 43.0 2.821 3.311 110.5 16.6 9.4
2022 05 11 18 45.09 +11 24.7 2.601 3.220 119.5 15.8 9.1
2022 05 21 18 35.94 +10 45.8 2.395 3.130 128.8 14.6 8.9
2022 05 31 18 23.39 +09 38.3 2.210 3.041 138.0 12.9 8.6
2022 06 10 18 07.50 +07 53.8 2.054 2.952 146.2 11.0 8.3
2022 06 20 17 48.77 +05 26.4 1.932 2.864 151.1 9.9 8.1
2022 06 30 17 28.19 +02 15.8 1.850 2.776 149.9 10.6 7.9
2022 07 10 17 07.24 -01 30.8 1.811 2.690 142.5 13.3 7.7
2022 07 20 16 47.50 -05 39.5 1.815 2.605 131.9 16.9 7.6
2022 07 30 16 30.24 -09 54.6 1.855 2.522 120.2 20.4 7.6
2022 08 09 16 16.28 -14 04.1 1.923 2.441 108.4 23.2 7.5
2022 08 19 16 05.91 -18 01.2 2.011 2.362 97.2 25.2 7.5
2022 08 29 15 59.05 -21 44.4 2.109 2.286 86.8 26.2 7.5
2022 09 08 15 55.46 -25 15.1 2.210 2.214 77.0 26.3 7.5
2022 09 18 15 54.82 -28 36.2 2.307 2.145 68.0 25.8 7.5
2022 09 28 15 56.82 -31 50.8 2.395 2.080 59.8 24.6 7.4
2022 10 08 16 01.26 -35 02.3 2.470 2.020 52.3 23.0 7.4
2022 10 18 16 07.97 -38 13.5 2.529 1.966 45.6 21.2 7.4
2022 10 28 16 16.96 -41 27.2 2.570 1.919 40.0 19.5 7.3
2022 11 07 16 28.34 -44 45.8 2.592 1.878 35.7 17.9 7.3
2022 11 17 16 42.40 -48 11.4 2.594 1.845 33.0 17.0 7.2
2022 11 27 16 59.76 -51 45.7 2.577 1.820 32.2 16.8 7.1
2022 12 07 17 21.40 -55 29.1 2.544 1.804 33.4 17.5 7.1
2022 12 17 17 49.05 -59 19.9 2.497 1.797 36.1 18.8 7.0
2022 12 27 18 25.62 -63 12.0 2.440 1.799 39.9 20.5 7.0
2023 01 06 19 15.63 -66 49.6 2.380 1.811 44.3 22.3 6.9
2023 01 16 20 24.64 -69 39.8 2.321 1.831 48.9 23.9 6.9
2023 01 26 21 53.28 -70 48.7 2.271 1.859 53.3 25.1 6.9
2023 02 05 23 27.26 -69 28.7 2.238 1.896 57.3 25.9 7.0
2023 02 15 00 46.89 -65 44.4 2.227 1.940 60.4 26.3 7.0
2023 02 25 01 46.52 -60 24.8 2.243 1.991 62.5 26.2 7.1
2023 03 07 02 30.62 -54 20.3 2.288 2.047 63.5 25.7 7.3
2023 03 17 03 04.49 -48 07.1 2.362 2.109 63.2 24.9 7.5
2023 03 27 03 31.80 -42 08.8 2.461 2.176 61.8 23.8 7.7
2023 04 06 03 54.76 -36 39.0 2.582 2.247 59.5 22.6 7.9
2023 04 16 04 14.73 -31 44.3 2.718 2.321 56.6 21.1 8.1
2023 04 26 04 32.56 -27 26.2 2.863 2.398 53.1 19.6 8.3
2023 05 06 04 48.76 -23 43.8 3.012 2.478 49.5 18.0 8.5
NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.
(C) Copyright 2021 CBAT
2021 May 12 (CBET 4966) Daniel W. E. Green
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