OAA computing section circular NK 528 Periodic Comet Forbes
The following improved orbital elements, by S. Nakano, are from 54 observations 1974 to 1987, including full planetary perturbations and non-gravitational effect of style II. The mean residual is +/- 0.72 arc second. Epoch = 1987 Jan. 5.0 ET T = 1987 Jan. 1.66270 +/- 0.00202 (m.e.) ET Peri. = 262.71600 +/- 0.00049 Node = 22.91075 +/- 0.00027 (1950.0) Inc. = 4.66512 +/- 0.00004 q = 1.4745719 +/- 0.0000016 AU e = 0.5656687 +/- 0.0000003 a = 3.3950396 +/- 0.0000007 AU n = 0.15755667 +/- 0.00000005 P = 6.256 +/- 0.0000019 years A1 = +0.815 +/- 0.035 A2 = -0.06243 +/- 0.00099 (T = 1961 July 24.80024 ET Epoch = 1961 Aug. 9.0 ET Peri. = 259.72234 e = 0.5530031 Node = 25.39489 (1950.0) a = 3.4557403 AU Inc. = 4.61974 n = 0.15342369 q = 1.5447053 AU P = 6.424 years ) T = 1967 Dec. 22.50861 ET Epoch = 1967 Dec. 16.0 ET Peri. = 259.79599 e = 0.5534787 Node = 25.29401 (1950.0) a = 3.4513721 AU Inc. = 4.62363 n = 0.15371505 q = 1.5411111 AU P = 6.412 years T = 1974 May 19.85593 ET Epoch = 1974 June 2.0 ET Peri. = 259.91860 e = 0.5550655 Node = 25.20182 (1950.0) a = 3.4456468 AU Inc. = 4.62460 n = 0.15409833 q = 1.5330871 AU P = 6.396 years T = 1980 Sept.24.77424 ET Epoch = 1980 Oct. 8.0 ET Peri. = 262.53883 e = 0.5648775 Node = 23.01816 (1950.0) a = 3.3991810 AU Inc. = 4.66500 n = 0.15726882 q = 1.4790602 AU P = 6.267 years The predicted orbit for the 1993 return is as follows: T = 1993 Mar. 14.63221 ET Epoch = 1993 Apr. 3.0 ET Peri. = 310.55534 e = 0.5680485 Node = 333.73834 (1950.0) a = 3.3495517 AU Inc. = 7.15298 n = 0.16077705 q = 1.4468438 AU P = 6.130 years - continued - P/Forbes NK 528 - 2 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 01 19.51383 16 06 04.01 -21 49 02.8 1.0+ 0.3- 691/ST 1974 01 19.54508 16 06 08.60 -21 49 18.7 1.4- 0.2+ 691/ST 1974 02 25.49228 17 49 15.12 -25 39 12.0 0.3- 0.4- 691/ST 1974 02 25.51817 17 49 19.75 -25 39 17.2 0.4- 0.4- 691/ST 1974 03 22.48084 19 07 04.61 -25 55 52.7 0.6+ 0.6- 691/ST 1974 03 22.49676 19 07 07.60 -25 55 50.8 0.2+ 0.5- 691/ST 1974 04 20.45347 20 38 59.27 -23 25 27.0 0.4+ 1.1- 693/CT 1974 04 20.47361 20 39 03.00 -23 25 17.5 0.8+ 1.2- 693/CT 1974 04 22.39049 20 44 57.66 -23 09 20.0 0.4- 0.6- 805/EL 1974 04 24.36192 20 51 00.13 -22 52 23.6 0.2- 0.1- 805/EL 1974 04 25.34243 20 53 58.79 -22 43 49.2 ( 8.7- 4.9-) 805/EL 1974 04 26.77639 20 58 20.2 -22 30 56 0.9- 0.5+ 372/sk Y 1974 05 02.76667 21 16 12.04 -21 33 48.5 ( 3.0- 2.3+) 372/sk 1974 05 02.77639 21 16 13.80 -21 33 42.9 ( 2.1- 2.3+) 372/sk 1974 06 14.94444 23 04 04.75 -13 46 05.8 1.0+ 1.8+ 076/HB 1974 06 14.95833 23 04 06.77 -13 45 57.2 ( 7.1+ 2.2+) 076/HB 1974 07 24.70104 23 52 57.02 -09 16 09.8 1.0- 1.2+ 372/sk 1974 08 17.05680 23 51 09.97 -08 56 49.2 ( 5.9- 1.9-) 993/WL 1974 08 20.74792 23 48 58.4 -09 00 42 1.5+ 0.6- 396/tc Y 1974 09 11.31823 23 30 54.62 -09 28 48.6 0.4- 0.7- 691/ST 1974 09 11.32738 23 30 54.08 -09 28 49.2 0.6- 0.9- 691/ST 1974 09 11.92380 23 30 22.25 -09 29 22.1 ( 3.3+ 3.9-) 095/CR 1974 09 14.86788 23 27 46.20 -09 31 06.6 1.1- 0.1+ 095/CR 1974 09 15.69444 23 27 03.1 -09 31 29 ( 0.9- 3.4-) 372/sk Y 1974 10 08.47934 23 12 57.5 -09 04 39 ( 2.3- 2.1+) 372/sk Y 1974 10 09.13590 23 12 45.18 -09 02 42.0 0.7+ 0.4+ 805/EL 1974 10 10.12717 23 12 28.04 -08 59 48.4 0.4+ 0.7+ 805/EL 1974 10 12.17475 23 11 57.77 -08 53 35.5 ( 2.5- 0.7-) 801/HO 1974 10 13.61319 23 11 41.4 -08 48 43 ( 2.6+ 1.8+) 372/sk Y 1974 10 18.15046 23 11 12.41 -08 31 48.0 0.1- 0.1+ 801/HO 1980 03 12.26854 13 37 05.08 -08 36 11.6 0.4- 0.0 809/ES 1980 03 13.26041 13 36 44.35 -08 35 51.6 0.3+ 0.9+ 801/HO 1980 03 13.32389 13 36 42.65 -08 35 50.4 ( 2.6- 0.2+) 801/HO 1980 03 14.21771 13 36 22.67 -08 35 13.8 0.9- 0.0 809/ES 1980 04 14.02561 13 12 26.05 -07 25 41.3 0.2+ 0.8+ 805/EL 1980 04 15.09505 13 11 18.32 -07 22 05.7 0.2+ 0.7+ 805/EL 1980 04 16.15952 13 10 10.55 -07 18 31.1 0.3+ 0.2- 805/EL 1980 04 18.60293 13 07 34.65 -07 10 24.1 0.7+ 0.6+ 381/ks 1980 04 18.63207 13 07 32.76 -07 10 18.1 1.4+ 0.7+ 381/ks 1980 05 17.18929 12 42 48.76 -06 09 22.2 0.2- 1.1- 801/HO 1980 06 06.57234 12 40 12.81 -06 51 23.3 0.6+ 0.2- 381/ks 1980 06 13.09867 12 42 42.07 -07 23 25.4 1.1- 0.2+ 801/HO 1980 07 06.30214 13 03 52.78 -10 23 56.3 ( 3.4- 0.8+) 474/JN 1980 07 06.33962 13 03 55.76 -10 24 18.5 1.4- 0.5+ 474/JN 1980 09 03.47847 15 10 49.81 -22 18 21.2 0.7- 0.1+ 323/PR 1980 09 17.49653 15 54 10.79 -24 46 37.4 1.4+ 0.4- 323/PR 1986 04 08.26431 11 11 10.55 +08 33 43.9 1.5+ 1.5- 675/PL 1986 04 08.27181 11 11 10.09 +08 33 46.2 0.1+ 0.6- 675/PL 1986 05 09.21506 10 57 09.63 +08 57 56.3 0.8+ 1.1- 675/PL 1986 05 09.22251 10 57 09.58 +08 57 55.5 0.7+ 1.1- 675/PL - continued - P/Forbes NK 528 - 3 Date/ UT R.A. (1950) Decl. *** O-C *** Code/Obs. h m s . , " " " 1986 06 09.20410 11 06 57.06 +06 56 53.7 0.8- 0.4+ 675/PL 1986 06 09.21167 11 06 57.35 +06 56 51.1 0.9- 0.5+ 675/PL 1986 06 10.21562 11 07 38.32 +06 50 46.4 0.8- 0.0 675/PL 1986 06 10.22417 11 07 38.65 +06 50 43.4 1.0- 0.2+ 675/PL 1986 06 12.23681 11 09 04.48 +06 38 09.8 1.4- 0.3- 707/ev 1987 09 01.44563 03 13 50.96 +18 42 43.4 0.5+ 0.1- 691/ST 1987 09 01.45191 03 13 51.00 +18 42 44.1 0.4+ 0.2- 691/ST 1987 09 01.46944 03 13 51.13 +18 42 46.3 0.4+ 0.2- 691/ST 1987 09 01.47402 03 13 51.18 +18 42 46.7 0.7+ 0.4- 691/ST 1987 09 01.47872 03 13 51.18 +18 42 47.5 0.2+ 0.2- 691/ST 1987 09 19.44425 03 12 03.42 +19 03 52.3 0.0 0.6- 691/ST 1987 09 20.37704 03 11 43.27 +19 04 03.4 0.9- 0.3- 691/ST 1987 09 20.44269 03 11 41.76 +19 04 03.4 0.0 1.0- 691/ST 1987 10 16.35100 02 53 56.60 +18 31 51.3 0.4- 0.0 691/ST 1987 10 16.36808 02 53 55.64 +18 31 48.7 0.0 0.0 691/ST 1987 10 16.38238 02 53 54.79 +18 31 46.5 0.4- 0.0 691/ST ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 1988 November 3