OAA computing section circular NK 849 138P/Shoemaker-Levy 7
The following improved orbital elements, by S. Nakano, are from 50 observations 1991 to 1999. Perturbations by Mercury to Neptune and three minor planets, Ceres, Pallas and Vesta, were taken into account. The mean residual is +/- 0.67 arc second. See an orbit in NK625. Epoch = 1998 Aug. 15.0 TT T = 1998 Aug. 24.56519 +/- 0.00083 (m.e.) TT Peri. = 95.52247 +/- 0.00056 Node = 309.51815 +/- 0.00022 (2000.0) Inc. = 10.08889 +/- 0.00003 q = 1.6972013 +/- 0.0000042 AU e = 0.5311201 +/- 0.0000011 a = 3.6196928 +/- 0.0000034 AU n' = 0.14311874 +/- 0.00000020 P = 6.887 +/- 0.0000098 years T = 1991 Oct. 27.47734 TT Epoch = 1991 Oct. 31.0 TT Peri. = 91.91055 e = 0.5427282 Node = 312.96868 (2000.0) a = 3.5644096 AU Inc. = 10.27826 n'= 0.14646123 q = 1.6299041 AU P = 6.729 years The predicted orbit for the 2005 return is as follows: T = 2005 July 19.91611 TT Epoch = 2005 July 9.0 TT Peri. = 95.64978 e = 0.5294682 Node = 309.44331 (2000.0) a = 3.6284544 AU Inc. = 10.07933 n'= 0.14260067 q = 1.7073032 AU P = 6.912 years The following residuals in seconds of arc are from the above orbital elements: Date Code Residual(") Date Code Residual(") Date Code Residual(") 1991/ 911210 657 0.7+ 1.4+ 981114 867 0.2- 0.2- 911113 675 0.1- 0.1- 911210 657 1.4+ 0.4- 981114 867 0.4- 0.5- 911113 675 0.1- 0.9- 911211 372 (0.6+ 2.8+) 981114 867 0.7+ 0.9- 911115 675 1.5- 0.7- 911213 372 0.5+ 0.7+ 981115 360 1.1- 0.5- 911116 675 (4.5+ 0.9+) 911224 950 1.8- 0.7- 981115 360 0.9- 0.1- 911128 372 0.5+ 1.2+ 911224 950 0.8- 0.8+ 981115 360 1.0- 0.6- 911128 372 0.8- 0.4- 911229 372 1.3+ 0.8- 981123 693 0.4+ 0.4+ 911130 675 0.3+ 1.1+ 911230 372 0.6- 0.5- 981123 693 0.6+ 0.4+ 911130 675 0.1- 0.2- 1992/ 981123 693 0.7+ 0.4+ 911201 675 0.3+ 0.4- 920101 801 0.6+ 0.5- 981216 360 0.5- 0.3+ 911203 675 0.2+ 1.6- 920101 801 0.8+ 0.6- 981216 360 0.0 0.1+ 911204 372 1.0- 1.0+ 920106 801 0.5+ 0.4- 981216 360 0.3+ 0.1+ 911204 372 (2.3- 2.3+) 920106 801 0.4+ 0.4- 1999/ 911205 801 1.0+ 0.2+ 1998/ 990115 693 0.1+ 0.3- 911205 801 0.2+ 1.2+ 980725 691 0.7+ 0.2- 990115 693 0.1+ 0.4- 911206 801 0.5- 0.2- 980725 691 0.3+ 0.1+ 990115 693 0.1+ 0.5- 911206 801 (1.1- 3.1-) 980725 691 0.8+ 0.2- 990212 693 0.0 0.8+ 911208 372 (0.3- 2.5+) 980726 691 0.5- 0.2+ 990212 693 0.1- 0.8+ 911208 372 0.8- 1.1+ 980726 691 0.9- 0.1- 990212 693 0.0 0.4+ 911210 657 0.3- 0.8+ 980726 691 0.3+ 0.0 ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 2002 May 7