OAA computing section circular NK 721 137P/Shoemaker-Levy 2
The following improved orbital elements, by S. Nakano, are from 69 observations 1990-1999. Perturbations by Mercury to Neptune and three minor planets, Ceres, Pallas and Vesta, were taken into account. The mean residual is +/- 0.68 arc second. Epoch = 2000 Jan. 17.0 TT T = 2000 Feb. 5.82312 +/- 0.00055 (m.e.) TT Peri. = 142.02042 +/- 0.00030 Node = 234.75348 +/- 0.00027 (2000.0) Inc. = 4.65703 +/- 0.00002 q = 1.8685703 +/- 0.0000043 AU e = 0.5797055 +/- 0.0000009 a = 4.4458596 +/- 0.0000032 AU n' = 0.10514060 +/- 0.00000011 P = 9.374 +/- 0.0000101 years T = 1990 Sept.25.37452 TT Epoch = 1990 Sept.26.0 TT Peri. = 140.07007 e = 0.5822720 Node = 235.99423 (2000.0) a = 4.4142406 AU Inc. = 4.63744 n'= 0.10627230 q = 1.8439518 AU P = 9.274 years The predicted orbit for the 2009 return is as follows: T = 2009 May 13.56589 TT Epoch = 2009 May 9.0 TT Peri. = 140.81150 e = 0.5745113 Node = 233.12104 (2000.0) a = 4.5013625 AU Inc. = 4.85368 n'= 0.10320200 q = 1.9152789 AU P = 9.550 years The following residuals in seconds of arc are from the above orbital elements: 1990/ 980519 696 0.3- 0.6+ 990713 159 0.0 0.2- 900917 675 (0.4- 2.5-) 980519 696 0.3- 0.2+ 990713 704 0.0 0.3- 900917 675 0.8+ 2.0- 980520 696 0.1- 0.2- 990713 704 0.5+ 0.6+ 900920 675 (0.8+ 3.5-) 980520 696 0.6+ 0.0 990713 704 0.9+ 0.2+ 901014 675 0.6- 1.3- 980520 696 0.7+ 0.1+ 990713 704 0.0 0.4+ 901016 675 0.4- 0.7- 1999/ 990713 704 0.5+ 0.7+ 901025 675 0.2- 0.6+ 990708 360 0.3- 0.3- 990713 159 0.7- 0.4- 901025 675 0.9- 0.2- 990708 360 0.4- 0.2- 990713 159 1.1- 0.1- 901113 675 0.8+ 0.3+ 990708 360 0.5- 0.2- 990716 122 1.1+ 0.2+ 901113 675 0.4+ 1.6- 990708 627 0.8- 1.4+ 990716 122 0.1- 0.2+ 901115 675 0.9- 1.4+ 990708 627 1.1+ 1.0- 990716 122 0.4+ 0.0 901115 675 1.7+ 0.4- 990708 627 0.4- 0.5+ 990716 122 0.1+ 0.2+ 901207 688 0.7+ 0.8+ 990708 627 1.0- 0.5- 990723 402 0.6- 0.5- 901207 688 0.7+ 0.7+ 990709 627 1.0+ 1.1- 990723 402 0.5- 0.5- 901207 372 (2.3- 0.2+) 990709 627 1.2- 0.4+ 990723 402 0.6- 0.3- 901207 372(11.8- 1.1+) 990709 627 0.6+ 0.2+ 990723 402 0.3- 0.4- 901211 568 1.5- 0.5+ 990712 627 0.2+ 0.8+ 990724 402 1.2- 0.1+ 901212 568 0.7- 0.6+ 990712 159 0.2- 0.9- 990724 402 0.3- 0.3- 901215 801 0.1+ 0.8+ 990712 159 0.4+ 0.0 990724 402 0.9- 0.4- 901215 801 0.2+ 0.5+ 990712 159 0.6+ 0.0 990724 402 0.8- 0.2- 901218 413 0.3- 0.8+ 990712 627 0.9+ 2.0+ 990912 695 1.4+ 0.0 1991/ 990712 159 0.8+ 0.4+ 990912 695 1.6+ 0.1- 910115 688 0.5- 0.4+ 990712 159 0.0 0.3- 990914 046 0.5- 0.6+ 910115 688 0.6+ 0.6+ 990712 627 0.0 0.9+ 990914 046 0.2- 0.3+ 1998/ 990712 159 0.4+ 0.0 990914 046 0.2- 0.7+ 980519 696 0.2- 0.2+ 990712 159 0.1- 0.4+ ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 1999 Nov. 4