OAA computing section circular NK 630 52P/Harrington-Abell
The following improved orbital elements, by S. Nakano, are from 34 observations 1968 to 1990. Perturbations by Mercury to Pluto and five minor planets, Ceres, Pallas, Vesta, Iris, Bamberga were taken into account. The mean residual is +/- 0.92 arc second. T = 1991 July 6.92887 TT Epoch = 1991 July 3.0 TT Peri. = 138.66468 e = 0.5404403 Node = 337.34467 (2000.0) a = 3.8610562 AU Inc. = 10.18274 n'= 0.12991069 q = 1.7743859 AU P = 7.587 years T = 1969 May 10.81954 TT Epoch = 1969 May 19.0 TT Peri. = 338.09239 e = 0.5240495 Node = 146.58090 (2000.0) a = 3.7260696 AU Inc. = 16.83242 n'= 0.13703378 q = 1.7734246 AU P = 7.192 years T = 1976 Apr. 21.81859 TT Epoch = 1976 Apr. 12.0 TT Peri. = 138.44502 e = 0.5400977 Node = 337.49005 (2000.0) a = 3.8616025 AU Inc. = 10.17066 n'= 0.12988313 q = 1.7759597 AU P = 7.588 years T = 1983 Dec. 1.66991 TT Epoch = 1983 Dec. 12.0 TT Peri. = 138.56630 e = 0.5388409 Node = 337.43054 (2000.0) a = 3.8708114 AU Inc. = 10.16103 n'= 0.12941990 q = 1.7850600 AU P = 7.616 years The predicted orbit for the 1999 return is as follows: T = 1999 Jan. 27.87246 TT Epoch = 1999 Jan. 22.0 TT Peri. = 138.90073 e = 0.5429119 Node = 337.28843 (2000.0) a = 3.8416804 AU Inc. = 10.21859 n'= 0.13089475 q = 1.7559865 AU P = 7.530 years The following residuals in seconds of arc are from the above orbital elements: Date Code Residual(") Date Code Residual(") Date Code Residual(") 681123 693 1.3- 0.1+ 760102 801 0.7+ 0.0 840326 323 1.4- 0.1- 681123 693 0.0 0.7+ 760126 691 (3.0+ 0.5-) 840402 801 2.0+ 0.1+ 690216 693 1.9+ 0.5+ 760126 691 (2.7+ 0.4-) 900918 675 0.7- 0.1+ 690216 693 1.3+ 0.3+ 760224 801 2.2- 0.6- 900918 675 0.8- 0.7- 690419 693 1.6- 1.4- 760225 691 0.5+ 0.4- 901022 691 1.0- 0.2- 690420 693 0.1- 0.8+ 830917 675 0.5+ 0.4+ 901022 691 0.8- 0.3- 751006 691 (3.4+ 0.7-) 830918 675 1.8+ 0.7- 901022 691 0.8- 0.0 751006 691 (3.8- 2.4+) 831203 707 1.3- 0.4+ 901023 691 0.5- 0.3- 751007 801 1.1- 0.5- 840108 707 0.9+ 1.8- 901023 691 0.3+ 0.5- 751101 691 0.7+ 0.5+ 840201 323 0.7- 1.7- 901023 691 0.1- 0.5- 751101 691 1.6- 0.4+ 840206 323 0.2+ 0.2- 901023 586 1.9+ 1.2+ 751204 801 0.8+ 0.5+ 840208 801 0.5+ 0.3+ 901023 586 0.7+ 0.8+ 751205 691 (0.3- 3.8+) 840227 323 1.0- 0.8+ 751205 691 (2.6- 0.4+) 840301 801 0.7- 0.4+ ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 1996 Apr. 11