OAA computing section circular NK 478 Periodic Comet Forbes 1961 VI = 1974 IX = 1980 VI
The following improved orbital elements, by S. Nakano, are from 65 observations 1961 to 1980, including full planetary per -turbations and non-gravitational effect of style II. The mean residual is +/- 1.60 arc seconds. Epoch = 1980 Oct. 8.0 ET T = 1980 Sept.24.77128 +/- 0.00099 (m.e.) ET Peri. = 262.53959 +/- 0.00268 Node = 23.01722 +/- 0.00267 (1950.0) Inc. = 4.66526 +/- 0.00008 q = 1.4790458 +/- 0.0000047 AU e = 0.5648822 +/- 0.0000011 a = 3.3991845 +/- 0.0000063 AU nß = 0.15726858 +/- 0.000000007 P = 6.267 +/- 0.0000173 years A1 = +0.665 +/- A2 = -0.07905 +/- T = 1961 July 24.75698 ET Epoch = 1961 Aug. 9.0 ET Peri. = 259.72073 e = 0.5530123 Node = 25.39414 (1950.0) a = 3.4557887 AU Inc. = 4.61999 nß= 0.15342047 q = 1.5446950 AU P = 6.424 years [ T = 1967 Dec. 22.49397 ET Epoch = 1967 Dec. 16.0 ET Peri. = 259.79502 e = 0.5534865 Node = 25.29326 (1950.0) a = 3.4514076 AU Inc. = 4.62388 nß= 0.15371268 q = 1.5411002 AU P = 6.412 years ] T = 1974 May 19.85504 ET Epoch = 1974 June 2.0 ET Peri. = 259.91842 e = 0.5550714 Node = 25.20107 (1950.0) a = 3.4456659 AU Inc. = 4.62485 nß= 0.15409705 q = 1.5330755 AU P = 6.396 years The predicted orbit for the 1987 return is as follows: The comet will pass 0.36 AU from Jupiter on 1990 August 30. T = 1987 Jan. 1.63977 ET Epoch = 1987 Jan. 5.0 ET Peri. = 262.71745 e = 0.5656718 Node = 22.90981 (1950.0) a = 3.3950282 AU Inc. = 4.66538 nß= 0.15755747 q = 1.4745566 AU P = 6.256 years There are the residuals, in seconds of arc, from the above orbital elements on the next pages: - continued - NK 478 - 2 Date/ UT R.A. (1950) Decl. *** O-C *** Code/Obs. h m s ¡ , " " " 1961 01 16.50412 14 33 52.68 -14 23 30.0 0.6+ 0.5+ 689/FS 1961 02 13.44056 15 17 59.99 -18 13 29.0 1.3- 1.1+ 689/FS 1961 02 13.51120 15 18 06.52 -18 14 02.4 0.6- 0.7+ 689/FS 1961 03 19.44685 16 07 46.06 -22 19 58.2 1.0- 0.4+ 689/FS 1961 03 22.44796 16 11 41.37 -22 40 38.6 0.4- 0.4- 689/FS 1961 03 22.47567 16 11 43.41 -22 40 49.9 0.9- 0.2- 689/FS 1961 04 09.48991 16 32 32.86 -24 45 16.7 1.5- 0.3- 689/FS 1961 04 16.39696 16 38 57.46 -25 34 21.4 2.3- 1.7- 689/FS 1961 04 16.41987 16 38 58.60 -25 34 30.4 1.7- 0.8- 689/FS 1961 05 08.40634 16 51 28.42 -28 19 55.8 1.0- 0.4- 689/FS 1961 05 08.43343 16 51 28.78 -28 20 08.4 0.4- 0.5- 689/FS 1961 06 04.30494 16 49 28.33 -31 40 27.5 0.3- 1.5- 689/FS 1961 06 04.32022 16 49 27.96 -31 40 33.2 0.4- 1.3- 689/FS 1961 07 05.22623 16 47 05.24 -33 44 57.3 0.5- 2.5- 689/FS 1961 07 05.24428 16 47 05.58 -33 44 58.8 0.6- 2.4- 689/FS 1961 09 11.15664 18 45 19.56 -30 28 21.5 1.8+ 0.4- 689/FS 1961 09 11.16706 18 45 20.93 -30 28 17.1 0.1- 0.7- 689/FS 1961 10 12.09766 20 02 11.55 -25 38 47.4 1.7+ 0.5- 689/FS 1961 10 12.12301 20 02 15.21 -25 38 30.7 2.3+ 0.4- 689/FS 1961 11 11.09663 21 11 24.94 -19 41 23.3 4.9+ 0.6+ 689/FS 1961 11 11.14420 21 11 31.05 -19 40 46.0 4.1+ 1.6+ 689/FS 1961 12 05.09740 22 01 49.41 -14 30 12.1 1.6+ 1.8+ 689/FS 1974 01 19.51383 16 06 04.01 -21 49 02.8 4.0+ 0.8- 691/ST 1974 01 19.54508 16 06 08.60 -21 49 18.7 1.6+ 0.3- 691/ST 1974 02 25.49228 17 49 15.12 -25 39 12.0 2.1+ 0.0 691/ST 1974 02 25.51817 17 49 19.75 -25 39 17.2 1.9+ 0.0 691/ST 1974 03 22.48084 19 07 04.61 -25 55 52.7 2.2+ 0.3+ 691/ST 1974 03 22.49676 19 07 07.60 -25 55 50.8 1.8+ 0.4+ 691/ST 1974 04 20.45347 20 38 59.27 -23 25 27.0 0.8+ 0.2+ 693/CT 1974 04 20.47361 20 39 03.00 -23 25 17.5 1.2+ 0.1+ 693/CT 1974 04 22.39049 20 44 57.66 -23 09 20.0 0.1- 0.6+ 805/EL 1974 04 24.36192 20 51 00.13 -22 52 23.6 0.0 1.1+ 805/EL 1974 04 25.34243 20 53 58.79 -22 43 49.2 ( 8.5- 3.6-) 805/EL 1974 04 26.77639 20 58 20.2 -22 30 56 0.7- 1.7+ 372/sk Y 1974 05 02.76667 21 16 12.04 -21 33 48.5 3.1- 3.6+ 372/sk 1974 05 02.77639 21 16 13.80 -21 33 42.9 2.2- 3.5+ 372/sk 1974 06 14.94444 23 04 04.75 -13 46 05.8 0.2- 2.9+ 076/HB 1974 06 14.95833 23 04 06.77 -13 45 57.2 ( 5.8+ 3.3+) 076/HB 1974 07 24.70104 23 52 57.02 -09 16 09.8 2.4- 2.1+ 372/sk 1974 08 17.05680 23 51 09.97 -08 56 49.2 ( 7.0- 1.2-) 993/WL 1974 08 20.74792 23 48 58.4 -09 00 42 0.4+ 0.0 396/tc Y 1974 09 11.31823 23 30 54.62 -09 28 48.6 1.2- 0.3- 691/ST 1974 09 11.32738 23 30 54.08 -09 28 49.2 1.4- 0.4- 691/ST 1974 09 11.92380 23 30 22.25 -09 29 22.1 2.6+ 3.5- 095/CR 1974 09 14.86788 23 27 46.20 -09 31 06.6 1.9- 0.5+ 095/CR 1974 09 15.69444 23 27 03.1 -09 31 29 1.6- 3.0- 372/sk Y 1974 10 08.47934 23 12 57.5 -09 04 39 2.7- 2.3+ 372/sk Y 1974 10 09.13590 23 12 45.18 -09 02 42.0 0.3+ 0.6+ 805/EL 1974 10 09.77479 23 12 33.64 -09 00 49.6 ( 6.6- 11.4+) 095/CR 1974 10 10.12717 23 12 28.04 -08 59 48.4 0.1- 0.9+ 805/EL - continued - NK 478 - 3 Date/ UT R.A. (1950) Decl. *** O-C *** Code/Obs. h m s ¡ , " " " 1974 10 12.17475 23 11 57.77 -08 53 35.5 2.9- 0.5- 801/HO 1974 10 13.61319 23 11 41.4 -08 48 43 2.2+ 2.0+ 372/sk Y 1974 10 18.15046 23 11 12.41 -08 31 48.0 0.4- 0.2+ 801/HO 1980 03 12.26854 13 37 05.08 -08 36 11.6 0.5+ 0.4- 809/ES 1980 03 13.26041 13 36 44.35 -08 35 51.6 1.2+ 0.5+ 801/HO 1980 03 13.32389 13 36 42.65 -08 35 50.4 1.7- 0.2- 801/HO 1980 03 14.21771 13 36 22.67 -08 35 13.8 0.1- 0.3- 809/ES 1980 04 14.02561 13 12 26.05 -07 25 41.3 1.4+ 0.8+ 805/EL 1980 04 15.09505 13 11 18.32 -07 22 05.7 1.3+ 0.7+ 805/EL 1980 04 16.15952 13 10 10.55 -07 18 31.1 1.5+ 0.3- 805/EL 1980 04 18.60293 13 07 34.65 -07 10 24.1 1.9+ 0.6+ 381/ks 1980 04 18.63207 13 07 32.76 -07 10 18.1 2.6+ 0.7+ 381/ks 1980 05 17.18929 12 42 48.76 -06 09 22.2 1.1+ 0.7- 801/HO 1980 06 06.57234 12 40 12.81 -06 51 23.3 1.7+ 0.4+ 381/ks 1980 06 13.09867 12 42 42.07 -07 23 25.4 0.1- 1.0+ 801/HO 1980 07 06.30214 13 03 52.78 -10 23 56.3 3.0- 2.0+ 474/JN 1980 07 06.33962 13 03 55.76 -10 24 18.5 1.0- 1.8+ 474/JN 1980 09 03.47847 15 10 49.81 -22 18 21.2 2.9- 2.1+ 323/PR 1980 09 17.49653 15 54 10.79 -24 46 37.4 1.6- 1.5+ 323/PR ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 1985 July 9