OAA computing section circular NK 476 Periodic Comet West-Kohoutek-Ikemura 1975 IV = 1981 VIII
The following improved orbital elements, by S. Nakano, are from 36 observations 1974 to 1981: Perturbations by all nine planets were taken into account. The mean residual is +/- 1.31 arc seconds. Epoch = 1981 Apr. 26.0 ET T = 1981 Apr. 11.08876 +/- 0.00162 (m.e.) ET Peri. = 358.12754 +/- 0.00058 Node = 84.60943 +/- 0.00056 (1950.0) Inc. = 30.06573 +/- 0.00024 q = 1.4007178 +/- 0.0000039 AU e = 0.5812698 +/- 0.0000011 a = 3.3451558 +/- 0.0000011 AU nß = 0.16109407 +/- 0.000000001 P = 6.118 +/- 0.0000031 years T = 1975 Feb. 25.78383 ET Epoch = 1975 Mar. 9.0 ET Peri. = 358.00747 e = 0.5817185 Node = 84.65755 (1950.0) a = 3.3430100 AU Inc. = 30.07977 nß= 0.16124920 q = 1.3983192 AU P = 6.112 years The predicted orbit for the 1987 return is as follows: T = 1987 July 27.38691 ET Epoch = 1987 July 24.0 ET Peri. = 359.83379 e = 0.5444304 Node = 83.52676 (1950.0) a = 3.4474821 AU Inc. = 30.57850 nß= 0.15397530 q = 1.5705679 AU P = 6.401 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 ( 0.6- 9.3+) 809/we 1974 10 15.1701 01 05 47.12 -49 57 54.0 ( 6.2+ 8.2+) 809/we 1975 02 27.77604 02 46 23.63 +15 48 36.6 1.6- 1.9- 029/HM 1975 02 27.78437 02 46 25.07 +15 48 54.3 1.3+ 1.0- 029/HM 1975 02 28.42674 02 48 01.44 +16 10 29.7 ( 6.4- 4.5-) 380/kj 1975 02 28.44063 02 48 03.57 +16 10 55.8 ( 5.7- 6.2-) 380/kj 1975 02 28.46510 02 48 07.79 +16 11 51.0 2.2+ 0.1- 882/sz 1975 02 28.47083 02 48 08.46 +16 12 00.8 0.6- 1.8- 882/sz 1975 02 28.47778 02 48 10.3 +16 12 16 (10.8+ 0.8-) 372/sk Y 1975 02 28.48854 02 48 11.5 +16 12 39.7 ( 4.8+ 1.3+) 372/sk 1975 03 01.02397 02 49 33.23 +16 30 37.4 (10.4+ 3.7+) 801/sw 1975 03 01.44352 02 50 37.05 +16 44 30.2 ( 9.2+ 4.1-) 379/ik 1975 03 02.43507 02 53 09.19 +17 17 24.9 (10.9+ 3.4-) 379/ik 1975 03 02.45035 02 53 10.65 +17 17 51.5 ( 1.6- 7.0-) 379/ik 1975 03 02.46215 02 53 12.82 +17 18 17.4 ( 3.6+ 4.3-) 882/sz - continued - NK 476 - 2 Date/ UT R.A. (1950) Decl. *** O-C *** Code/Obs. h m s ¡ , " " " 1975 03 03.44375 02 55 44.48 +17 50 42.4 1.5+ 2.5+ 380/kj 1975 03 03.46354 02 55 47.51 +17 51 19.9 1.2+ 1.2+ 380/kj 1975 03 03.51597 02 55 55.80 +17 53 02.7 ( 3.9+ 1.2+) 372/sk 1975 03 03.52361 02 55 56.86 +17 53 15.0 2.1+ 1.4- 372/sk 1975 03 04.08866 02 57 24.63 +18 11 43.1 1.8- 0.3- 801/HO 1975 03 05.02830 02 59 51.97 +18 42 13.5 1.7- 0.5- 801/HO 1975 03 05.18542 03 00 17.02 +18 47 16.6 ( 3.7+ 2.2-) 688/LO 1975 03 06.81609 03 04 35.55 +19 39 27.3 ( 0.2- 6.8-) 020/ml 1975 03 07.13617 03 05 26.60 +19 49 47.2 1.9- 2.0+ 691/ST 1975 03 07.14254 03 05 27.61 +19 49 59.3 1.9- 2.0+ 691/ST 1975 03 07.48889 03 06 23.32 +20 00 56.1 0.4+ 1.2+ 372/sk 1975 03 07.49722 03 06 24.67 +20 01 10.3 0.7+ 0.3- 372/sk 1975 03 08.43125 03 08 55.30 +20 30 35.0 0.8- 0.4+ 380/kj 1975 03 08.43836 03 08 56.47 +20 30 47.1 0.4- 0.8- 380/kj 1975 03 10.18160 03 13 40.51 +21 24 55.1 ( 4.4- 0.7-) 702/he 1975 03 10.19410 03 13 42.89 +21 25 17.2 0.3+ 1.5- 702/JC 1975 03 10.19896 03 13 43.63 +21 25 27.6 0.5- 0.1- 702/JC 1975 03 14.16979 03 24 47.10 +23 25 08.0 0.3- 1.8- 702/JC 1975 03 14.17951 03 24 48.90 +23 25 28.2 1.8+ 1.3+ 702/JC 1975 03 16.49618 03 31 26.12 +24 32 51.1 2.5+ 0.3- 372/sk 1975 03 16.50347 03 31 27.44 +24 33 05.6 3.4+ 1.7+ 372/sk 1975 03 16.82257 03 32 22.53 +24 42 08.7 0.8- 2.3- 029/HM 1975 03 20.83403 03 44 09.57 +26 33 57.5 1.8- 1.5- 029/HM 1975 03 21.82083 03 47 06.98 +27 00 35.2 1.1- 0.2- 029/HM 1975 03 31.81580 04 18 18.45 +31 08 47.6 1.2+ 1.1+ 029/HM 1975 04 03.49097 04 27 02.19 +32 08 16.7 ( 3.9+ 2.2-) 372/sk 1975 04 11.09236 04 52 39.66 +34 40 32.1 0.3+ 0.2- 774/WN 1975 04 11.13056 04 52 48.09 +34 41 17.9 ( 6.8+ 4.1+) 774/kn 1975 04 12.68296 04 58 11.25 +35 09 13.6 (12.9+ 5.5+) 210/AA 1975 04 12.69674 04 58 13.69 +35 09 33.1 ( 7.5+ 10.7+) 210/AA 1975 04 18.03125 05 17 01.54 +36 36 50.9 1.2- 0.5- 801/HO 1975 05 04.95049 06 19 06.67 +39 46 24.4 ( 0.8- 5.4-) 993/su 1975 05 09.15972 06 34 51.07 +40 13 03.4 0.5+ 0.6+ 693/CT 1975 05 17.15833 07 04 41.96 +40 41 45.3 0.3- 1.6+ 691/ST 1975 05 17.18067 07 04 46.90 +40 41 47.3 0.6- 1.4+ 691/ST 1975 05 30.13709 07 52 02.05 +40 32 30.2 0.2- 1.3+ 801/HO 1980 10 09.64201 23 19 06.42 -52 45 26.2 0.0 0.9- 323/PR 1980 11 12.06181 23 05 00.26 -46 27 52.8 0.0 0.5+ 809/ES 1980 11 12.09167 23 05 00.69 -46 27 19.1 ( 0.1+ 4.3+) 809/ES 1980 12 02.05278 23 17 42.52 -40 12 21.5 0.8- 0.4+ 809/ES 1980 12 02.08056 23 17 44.14 -40 11 44.9 0.1+ 2.2+ 809/ES 1981 02 15.12571 01 22 37.67 -07 30 15.6 0.3- 0.5+ 675/PL ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 1985 July 7