OAA computing section circular NK 477 Periodic Comet Kohoutek 1975 III = 1981 IX
The following improved orbital elements, by S. Nakano, are from 29 observations 1975 to 1980: Perturbations by all nine planets were taken into account. The mean residual is +/- 1.05 arc seconds. Epoch = 1981 Apr. 26.0 ET T = 1981 Apr. 16.93128 +/- 0.00218 (m.e.) ET Peri. = 169.90649 +/- 0.00093 Node = 273.12344 +/- 0.00090 (1950.0) Inc. = 5.41636 +/- 0.00017 q = 1.5705723 +/- 0.0000047 AU e = 0.5365551 +/- 0.0000014 a = 3.3889086 +/- 0.0000018 AU nß = 0.15798443 +/- 0.000000002 P = 6.239 +/- 0.0000050 years T = 1975 Jan. 18.17814 ET Epoch = 1975 Jan. 28.0 ET Peri. = 169.74862 e = 0.5370193 Node = 273.19110 (1950.0) a = 3.3866787 AU Inc. = 5.41803 nß= 0.15814049 q = 1.5679668 AU P = 6.232 years The predicted orbit for the 1987 return is as follows: T = 1987 Oct. 29.75749 ET Epoch = 1987 Oct. 12.0 ET Peri. = 175.78928 e = 0.4976448 Node = 268.96534 (1950.0) a = 3.5356967 AU Inc. = 5.91924 nß= 0.14824893 q = 1.7761757 AU P = 6.648 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 ¡ , " " " 1975 02 09.77222 03 47 11.30 +19 25 38.9 2.0+ 0.6+ 029/kh 1975 02 27.79514 04 34 11.80 +20 12 46.3 1.4+ 0.6- 029/kh 1975 02 27.80417 04 34 13.18 +20 12 47.6 0.6+ 0.3- 029/kh 1975 03 05.08098 04 48 27.63 +20 22 06.2 0.2- 2.9+ 801/bg 1975 03 06.07608 04 51 09.56 +20 23 29.3 1.6- 0.1+ 801/mc 1975 03 07.18964 04 54 11.20 +20 24 59.5 0.1- 0.6+ 691/rm 1975 03 07.19792 04 54 12.52 +20 24 59.6 0.3- 0.2+ 691/rm 1975 03 07.52813 04 55 06.27 +20 25 26.8 2.1- 3.0+ 372/sk 1975 03 10.25764 05 02 33.04 +20 28 18.6 ( 6.0+ 0.8-) 702/he 1975 03 13.14306 05 10 25.58 +20 30 30.9 1.4- 0.1- 693/rm 1975 03 13.16944 05 10 30.0 +20 30 24 ( 0.6+ 7.7-) 693/rm Y 1975 03 16.55278 05 19 44.60 +20 31 48.0 ( 9.3- 1.9+) 372/sk 1975 03 16.83819 05 20 32.28 +20 31 46.6 0.1- 0.7- 029/kh 1975 03 16.85278 05 20 34.73 +20 31 47.5 0.9+ 0.2+ 029/kh 1975 03 17.84722 05 23 17.96 +20 31 51.0 0.4- 0.1+ 029/kh - continued - NK 477 - 2 Date/ UT R.A. (1950) Decl. *** O-C *** Code/Obs. h m s ¡ , " " " 1975 03 18.52465 05 25 08.70 +20 31 59.0 ( 6.0- 8.5+) 372/sk 1975 03 19.04144 05 26 34.08 +20 31 44.6 0.2- 1.7- 801/sw 1975 03 30.85347 05 58 45.63 +20 20 41.0 0.3- 1.6- 029/kh 1975 03 31.83368 06 01 24.76 +20 18 57.6 0.5- 0.1+ 029/kh 1975 04 01.07554 06 02 03.88 +20 18 30.4 1.2- 0.6- 801/sw 1975 04 03.50729 06 08 37.54 +20 13 31.3 0.4+ 1.0- 372/sk 1975 04 03.87102 06 09 36.37 +20 12 44.3 0.6+ 2.2+ 993/sy 1975 04 29.08907 07 15 32.16 +18 34 06.7 0.5- 0.9- 801/sa 1975 05 05.14931 07 30 40.13 +17 58 58.6 0.5+ 0.3- 691/rm 1975 05 05.18073 07 30 44.78 +17 58 46.8 0.7+ 0.4- 691/rm 1975 05 09.06368 07 40 16.68 +17 34 08.5 0.2- 0.4- 801/mc 1975 05 30.08625 08 29 36.09 +14 56 12.6 2.0+ 0.4- 801/mc 1976 04 29.30084 14 04 40.37 -19 11 42.8 0.1+ 1.5+ 691/rm 1976 04 29.31734 14 04 39.58 -19 11 38.1 0.3+ 1.4+ 691/rm 1980 08 06.27292 23 29 04.10 +04 32 37.0 0.3+ 1.1+ 809/ES 1980 08 07.31528 23 28 44.67 +04 33 55.0 0.8+ 0.5- 809/ES 1980 08 07.31562 23 28 44.4 +04 34 00 ( 3.2- 4.5+) 809/ES Y 1980 08 10.25556 23 27 40.2 +04 36 54 (23.3- 9.7+) 809/ES Y 1980 08 10.25584 23 27 41.69 +04 36 44.8 1.0- 0.5+ 809/ES 1980 09 12.17096 23 04 03.31 +03 29 25.6 ( 6.7- 1.3-) 801/HO 1980 09 16.16565 23 00 17.71 +03 10 08.7 0.9- 0.7+ 801/HO 1981 01 31.99483 00 32 53.95 +07 36 40.4 (26.2+ 6.5+) 801/HO ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 1985 July 7