OAA computing section circular NK 542 Periodic Comet West-Kohoutek-Ikemura
The following improved orbital elements, by S. Nakano, are from 45 observations 1974 to 1988, including full planetary perturbations and non-gravitational effect of style II. The mean residual is +/- 1.18 arc seconds. Epoch = 1987 July 24.0 ET T = 1987 July 27.26824 +/- 0.00066 (m.e.) ET Peri. = 359.83217 +/- 0.00101 Node = 83.52647 +/- 0.00018 (1950.0) Inc. = 30.57805 +/- 0.00008 q = 1.5705921 +/- 0.0000175 AU e = 0.5443962 +/- 0.0000057 a = 3.4472758 +/- 0.0000080 AU nß = 0.15398912 +/- 0.00000053 P = 6.401 +/- 0.0000222 years A1 = +0.425 +/- 0.079 A2 = -0.12249 +/- 0.00773 T = 1975 Feb. 25.78633 ET Epoch = 1975 Mar. 9.0 ET Peri. = 358.00943 e = 0.5817173 Node = 84.65733 (1950.0) a = 3.3430103 AU Inc. = 30.07955 nß= 0.16124918 q = 1.3983233 AU P = 6.112 years T = 1981 Apr. 11.08815 ET Epoch = 1981 Apr. 26.0 ET Peri. = 358.12728 e = 0.5812538 Node = 84.60921 (1950.0) a = 3.3450215 AU Inc. = 30.06552 nß= 0.16110377 q = 1.4007152 AU P = 6.118 years The predicted orbit for the 1993 return is as follows: T = 1993 Dec. 25.30696 ET Epoch = 1994 Jan. 8.0 ET Peri. = 359.96105 e = 0.5432690 Node = 83.48093 (1950.0) a = 3.4523453 AU Inc. = 30.54121 nß= 0.15365006 q = 1.5767930 AU P = 6.415 years The following residuals in seconds of arc are from the above orbital elements: Date/ UT R.A. (1950) Decl. *** O-C *** Code/Obs. h m s ¡ , " " " 1974 10 15.1285 01 05 50.08 -49 57 56.3 ( 6.9- 2.3+) 809/ES 1974 10 15.1701 01 05 47.12 -49 57 54.0 0.1- 1.2+ 809/ES 1975 02 27.77604 02 46 23.63 +15 48 36.6 1.5- 2.0- 029/HM 1975 02 27.78437 02 46 25.07 +15 48 54.3 1.4+ 1.2- 029/HM 1975 02 28.46510 02 48 07.79 +16 11 51.0 2.3+ 0.2- 882/sz 1975 02 28.47083 02 48 08.46 +16 12 00.8 0.5- 1.9- 882/sz 1975 02 28.48854 02 48 11.5 +16 12 39.7 ( 4.9+ 1.2+) 372/sk Y 1975 03 03.44375 02 55 44.48 +17 50 42.4 1.7+ 2.4+ 380/kj 1975 03 03.46354 02 55 47.51 +17 51 19.9 1.4+ 1.2+ 380/kj 1975 03 03.51597 02 55 55.80 +17 53 02.7 ( 4.1+ 1.2+) 372/sk - continued - P/West-Kohoutek-Ikemura NK 542 - 2 Date/ UT R.A. (1950) Decl. *** O-C *** Code/Obs. h m s ¡ , " " " 1975 03 03.52361 02 55 56.86 +17 53 15.0 2.3+ 1.5- 372/sk 1975 03 04.08866 02 57 24.63 +18 11 43.1 1.7- 0.3- 801/HO 1975 03 05.02830 02 59 51.97 +18 42 13.5 1.5- 0.5- 801/HO 1975 03 05.18542 03 00 17.02 +18 47 16.6 ( 3.9+ 2.2-) 688/LO 1975 03 07.13617 03 05 26.60 +19 49 47.2 1.7- 2.0+ 691/ST 1975 03 07.14254 03 05 27.61 +19 49 59.3 1.7- 2.0+ 691/ST 1975 03 07.48889 03 06 23.32 +20 00 56.1 0.7+ 1.2+ 372/sk 1975 03 07.49722 03 06 24.67 +20 01 10.3 0.9+ 0.3- 372/sk 1975 03 08.43125 03 08 55.30 +20 30 35.0 0.5- 0.5+ 380/kj 1975 03 08.43836 03 08 56.47 +20 30 47.1 0.1- 0.7- 380/kj 1975 03 10.19410 03 13 42.89 +21 25 17.2 0.5+ 1.5- 702/JC 1975 03 10.19896 03 13 43.63 +21 25 27.6 0.3- 0.0 702/JC 1975 03 14.16979 03 24 47.10 +23 25 08.0 0.0 1.7- 702/JC 1975 03 14.17951 03 24 48.90 +23 25 28.2 2.1+ 1.4+ 702/JC 1975 03 16.49618 03 31 26.12 +24 32 51.1 ( 2.9+ 0.2-) 372/sk 1975 03 16.50347 03 31 27.44 +24 33 05.6 ( 3.7+ 1.8+) 372/sk 1975 03 16.82257 03 32 22.53 +24 42 08.7 0.5- 2.2- 029/HM 1975 03 20.83403 03 44 09.57 +26 33 57.5 1.4- 1.4- 029/HM 1975 03 21.82083 03 47 06.98 +27 00 35.2 0.8- 0.0 029/HM 1975 03 31.81580 04 18 18.45 +31 08 47.6 1.6+ 1.3+ 029/HM 1975 04 11.09236 04 52 39.66 +34 40 32.1 0.6+ 0.0 774/WN 1975 04 12.68296 04 58 11.25 +35 09 13.6 (13.2+ 5.7+) 210/AA 1975 04 12.69674 04 58 13.69 +35 09 33.1 ( 7.9+ 10.8+) 210/AA 1975 04 18.03125 05 17 01.54 +36 36 50.9 0.8- 0.3- 801/HO 1975 05 09.15972 06 34 51.07 +40 13 03.4 0.6+ 0.8+ 693/CT 1975 05 17.15833 07 04 41.96 +40 41 45.3 0.4- 1.8+ 691/ST 1975 05 17.18067 07 04 46.90 +40 41 47.3 0.7- 1.6+ 691/ST 1975 05 30.13709 07 52 02.05 +40 32 30.2 0.4- 1.5+ 801/HO 1980 10 09.64201 23 19 06.42 -52 45 26.2 0.1+ 1.8- 323/PR 1980 11 12.06181 23 05 00.26 -46 27 52.8 0.3+ 0.3- 809/ES 1980 11 12.09167 23 05 00.69 -46 27 19.1 ( 0.3+ 3.4+) 809/ES 1980 12 02.05278 23 17 42.52 -40 12 21.5 0.5- 0.4- 809/ES 1980 12 02.08056 23 17 44.14 -40 11 44.9 0.5+ 1.3+ 809/ES 1981 02 15.12571 01 22 37.67 -07 30 15.6 0.1+ 0.0 675/PL 1987 09 27.47811 09 52 06.66 +26 53 05.9 1.0- 0.0 691/ST 1987 09 27.49516 09 52 09.73 +26 53 05.3 0.7- 0.4+ 691/ST 1987 10 01.82188 10 04 59.9 +26 47 11 0.9- 0.8+ 372/sk Y 1987 12 21.53117 13 17 53.62 +25 43 01.3 0.2- 1.1+ 691/ST 1987 12 21.55073 13 17 55.55 +25 43 05.3 0.5- 0.7+ 691/ST 1988 01 15.41334 13 52 29.11 +28 10 38.9 0.8+ 1.0- 691/ST 1988 01 15.42598 13 52 29.81 +28 10 45.5 0.4- 0.7- 691/ST 1988 01 15.42948 13 52 30.20 +28 10 45.8 1.8+ 2.1- 691/ST 1988 01 21.43425 13 58 20.01 +29 03 02.2 1.0- 0.6- 691/ST 1988 01 21.44027 13 58 20.15 +29 03 07.9 ( 3.2- 1.7+) 691/ST 1988 04 12.35436 13 22 26.99 +39 00 41.1 0.4- 1.9- 691/ST 1988 04 12.37066 13 22 25.90 +39 00 36.4 ( 0.4+ 3.0-) 691/ST 1988 04 12.37582 13 22 25.45 +39 00 34.3 ( 0.5- 4.0-) 691/ST ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 1990 May 3