OAA computing section circular NK 534 Periodic Comet Howell
The following improved orbital elements, by S. Nakano, are from 70 observations 1981 to 1988. Perturbations by all nine planets were taken into account. The mean residual is +/- 1.10 arc seconds. An orbit with nongravitational effect shows A1 = +0.28, A2 = -0.2588 and mean residuals = +/- 1.09 arc seconds. Epoch = 1987 Mar. 26.0 ET T = 1987 Apr. 14.53931 +/- 0.00079 (m.e.) ET Peri. = 214.74036 +/- 0.00176 Node = 75.31514 +/- 0.00173 (1950.0) Inc. = 5.56739 +/- 0.00021 q = 1.6121423 +/- 0.0000049 AU e = 0.5081016 +/- 0.0000015 a = 3.2773885 +/- 0.0000002 AU n = 0.16611628 +/- 0.00000001 P = 5.933 +/- 0.0000004 years T = 1981 May 4.35907 ET Epoch = 1981 Apr. 26.0 ET Peri. = 214.59054 e = 0.5075246 Node = 75.36168 (1950.0) a = 3.2797190 AU Inc. = 5.56803 n = 0.16593925 q = 1.6151810 AU P = 5.940 years The predicted orbit for the 1993 return is as follows. The comet will pass 0.53 AU from Jupiter on 1990 August. T = 1993 Feb. 26.09601 ET Epoch = 1993 Feb. 22.0 ET Peri. = 234.68175 e = 0.5520647 Node = 57.12024 (1950.0) a = 3.1458632 AU Inc. = 4.39668 n = 0.17664214 q = 1.4091431 AU P = 5.580 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 . , " " " 1981 08 29.35347 00 37 37.69 -07 34 32.1 2.2- 0.3- 675/PL 1981 08 31.43472 00 36 24.18 -07 44 51.5 1.2- 0.3- 675/PL 1981 09 01.66142 00 35 37.36 -07 50 47.6 2.7- 1.0+ 474/JN 1981 09 01.68330 00 35 36.37 -07 50 55.1 ( 3.9- 0.0 ) 474/JN 1981 09 02.45000 00 35 06.17 -07 54 56.6 1.6- 0.0 675/PL 1981 09 02.73097 00 34 54.56 -07 56 11.2 2.8- 1.0- 474/JN 1981 09 02.74104 00 34 54.21 -07 56 18.2 ( 1.6- 5.0-) 474/JN 1981 09 03.29306 00 34 32.21 -07 59 14.1 ( 0.1+ 3.7-) 688/LO 1981 09 03.33403 00 34 30.41 -07 59 26.0 ( 0.3+ 3.2-) 688/LO 1981 09 04.43403 00 33 43.46 -08 04 53.6 0.7- 0.4- 675/PL - continued - P/Howell NK 534 - 2 Date/ UT R.A. (1950) Decl. *** O-C *** Code/Obs. h m s . , " " " 1981 09 05.04730 00 33 16.75 -08 07 59.3 1.6- 0.8- 046/KL 1981 09 05.06166 00 33 16.20 -08 08 04.4 0.1+ 1.6- 046/KL 1981 09 05.23556 00 33 08.82 -08 08 54.2 2.0+ 0.1+ 801/HO 1981 09 06.53517 00 32 10.05 -08 15 09.6 1.7- 0.0 474/JN 1981 09 06.54832 00 32 09.57 -08 15 12.6 0.6+ 0.9+ 474/JN 1981 09 07.20690 00 31 39.18 -08 18 41.6 1.6+ 1.7- 801/HO 1981 09 09.28754 00 29 59.60 -08 28 45.5 1.3- 0.0 675/PL 1981 09 10.25698 00 29 11.89 -08 33 22.8 0.1+ 0.3- 675/PL 1981 09 10.50560 00 28 58.79 -08 34 33.5 0.0 0.6- 675/PL 1981 09 20.28580 00 20 21.07 -09 15 40.5 0.2- 0.5+ 675/PL 1981 09 21.34865 00 19 22.95 -09 19 22.9 0.6+ 0.9+ 675/PL 1981 09 22.21424 00 18 36.16 -09 22 19.7 1.8+ 2.6- 688/LO 1981 09 23.54942 00 17 23.14 -09 26 19.1 0.4- 0.7+ 474/JN 1981 09 23.56157 00 17 22.45 -09 26 21.4 0.4- 0.6+ 474/JN 1981 09 26.30208 00 14 55.46 -09 34 15.8 ( 2.1+ 4.1-) 688/LO 1981 09 26.33681 00 14 53.41 -09 34 21.3 ( 0.5+ 4.3-) 688/LO 1981 09 26.72188 00 14 33.01 -09 35 11.4 ( 3.5+ 3.0+) 372/sk 1981 09 26.96944 00 14 20.01 -09 35 52.7 0.2+ 0.3- 489/HF 1981 09 26.98125 00 14 19.41 -09 35 54.2 0.9+ 0.0 489/HF 1981 09 27.24740 00 14 05.46 -09 36 30.7 1.0+ 0.6+ 707/ev 1981 09 27.57500 00 13 48.37 -09 37 15.7 2.5+ 0.8+ 372/sk 1981 09 28.95278 00 12 36.28 -09 40 16.9 ( 3.0- 0.2+) 489/HF 1981 09 29.21800 00 12 22.75 -09 40 47.6 0.9+ 0.6+ 801/HO 1981 09 29.68021 00 11 58.91 -09 41 40.3 0.3- 0.6+ 372/sk 1981 10 04.25935 00 08 14.92 -09 48 11.0 1.9+ 1.1- 707/ev 1981 10 08.28474 00 05 16.16 -09 50 11.8 2.0+ 0.7+ 675/PL 1981 10 09.39516 00 04 30.15 -09 50 09.8 2.2+ 0.1+ 675/PL 1981 10 19.28335 23 59 00.68 -09 38 36.0 1.4+ 0.1+ 675/PL 1981 10 20.36634 23 58 33.34 -09 36 08.6 1.1- 0.5+ 675/PL 1981 11 02.07843 23 55 40.66 -08 51 44.8 0.1+ 0.0 801/HO 1981 11 17.14619 23 57 47.85 -07 27 57.0 0.0 1.4+ 675/PL 1981 11 17.15279 23 57 48.03 -07 27 55.0 0.9+ 0.9+ 675/PL 1981 11 23.05678 00 00 04.67 -06 48 04.4 ( 3.1+ 4.3+) 801/HO 1981 12 21.00260 00 19 21.18 -03 05 03.2 0.6+ 1.9- 801/HO 1982 01 15.10836 00 44 48.97 +00 41 36.9 1.6- 0.6- 675/PL 1982 01 16.09516 00 45 55.38 +00 50 43.2 0.6- 0.8- 675/PL 1987 03 06.67623 19 47 49.85 -22 04 10.4 0.4+ 0.5+ 474/JN 1987 03 06.70424 19 47 54.91 -22 03 59.9 1.8- 2.4+ 474/JN 1987 03 07.67624 19 50 56.46 -21 58 50.8 0.1+ 0.7- 474/JN 1987 03 07.69822 19 51 00.59 -21 58 41.7 0.6+ 1.4+ 474/JN 1987 06 23.45553 00 27 54.48 -03 49 01.4 0.9+ 1.5+ 688/LO 1987 06 23.45919 00 27 54.85 -03 48 59.6 0.8+ 1.6+ 688/LO 1987 07 22.47117 01 08 02.06 -01 07 18.1 ( 3.4+ 1.4+) 688/LO 1987 07 27.33446 01 12 29.71 -00 55 04.0 0.3+ 0.3+ 801/HO 1987 07 28.41326 01 13 23.33 -00 53 01.0 ( 3.1+ 2.5-) 657/VC 1987 08 02.44479 01 17 01.98 -00 46 07.2 2.1+ 1.0- 657/VC 1987 08 03.43646 01 17 39.04 -00 45 19.8 0.4+ 0.7- 657/VC 1987 08 07.41986 01 19 48.20 -00 44 02.0 1.9+ 0.4- 657/VC 1987 08 17.80208 01 22 46.99 -00 54 12.9 0.0 1.9- 323/PR 1987 08 19.34347 01 22 53.71 -00 57 29.2 1.2- 0.1+ 657/VC - continued - P/Howell NK 534 - 3 Date/ UT R.A. (1950) Decl. *** O-C *** Code/Obs. h m s . , " " " 1987 08 21.35667 01 22 54.70 -01 02 08.9 ( 2.2+ 3.2+) 657/VC 1987 08 24.34754 01 22 39.08 -01 10 22.1 0.1+ 0.8+ 801/HO 1987 08 26.62280 01 22 14.63 -01 17 28.9 ( 1.2+ 3.9-) 897/kj 1987 08 26.66817 01 22 13.84 -01 17 38.2 ( 1.6- 4.2-) 897/kj 1987 08 26.72431 01 22 13.45 -01 17 42.2 0.7+ 0.8- 323/PR 1987 08 31.42396 01 20 47.05 -01 34 44.9 0.3- 1.5+ 657/VC 1987 09 01.36250 01 20 24.49 -01 38 25.5 1.1- 0.6+ 691/ST 1987 09 01.36610 01 20 24.40 -01 38 26.5 0.9- 0.5+ 691/ST 1987 09 01.37069 01 20 24.28 -01 38 27.7 0.8- 0.4+ 691/ST 1987 09 01.40076 01 20 23.36 -01 38 40.7 ( 3.0- 3.8-) 657/VC 1987 09 02.86181 01 19 44.54 -01 44 23.6 0.2- 0.5- 323/PR 1987 09 04.47326 01 18 57.32 -01 51 20.3 0.4+ 1.7- 657/VC 1987 09 23.54722 01 04 32.90 -03 19 43.6 0.0 1.3+ 399/ue 1987 09 23.57986 01 04 31.01 -03 19 53.0 0.1- 0.8+ 399/ue 1987 09 28.99235 00 59 21.85 -03 43 18.1 ( 1.5- 5.0-) 491/CN 1987 10 19.20660 00 41 08.88 -04 36 09.4 ( 1.4- 4.0-) 657/VC 1987 10 19.23094 00 41 07.48 -04 36 06.2 1.1- 0.1+ 801/HO 1987 10 25.53698 00 36 45.93 -04 38 10.9 1.1- 0.1- 399/ue 1987 10 25.55226 00 36 45.37 -04 38 11.8 0.6- 1.3- 399/ue 1987 10 27.58403 00 35 33.22 -04 37 09.6 0.0 1.5- 323/PR 1987 11 17.04821 00 29 25.70 -03 48 28.4 0.8- 0.4+ 801/HO 1988 01 09.16015 00 56 20.62 +01 54 07.1 0.5- 1.0+ 675/PL 1988 01 09.16412 00 56 20.86 +01 54 09.1 0.0 1.1+ 675/PL 1988 01 09.17003 00 56 21.15 +01 54 12.0 0.4- 1.2+ 675/PL 1988 01 09.17341 00 56 21.31 +01 54 13.6 0.7- 1.2+ 675/PL 1988 01 13.20417 01 00 05.08 +02 26 33.3 0.8+ 1.3+ 675/PL 1988 01 13.21029 01 00 05.47 +02 26 36.6 1.5+ 1.6+ 675/PL ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 1989 May 15