OAA computing section circular NK 745 117P/Helin-Roman-Alu 1
The following improved orbital elements, by S. Nakano, are from 180 observations 1988-1999. Perturbations by Mercury to Neptune and three minor planets, Ceres, Pallas and Vesta, were taken into account. The mean residual is +/- 0.71 arc second. Epoch = 1997 Mar. 13.0 TT T = 1997 Mar. 26.87628 +/- 0.00063 (m.e.) TT Peri. = 215.07749 +/- 0.00012 Node = 73.47247 +/- 0.00009 (2000.0) Inc. = 9.74248 +/- 0.00002 q = 3.7148307 +/- 0.0000006 AU e = 0.1756998 +/- 0.0000001 a = 4.5066481 +/- 0.0000002 AU n' = 0.10302049 +/- 0.00000001 P = 9.567 +/- 0.0000007 years T = 1987 Oct. 12.39403 TT Epoch = 1987 Oct. 12.0 TT Peri. = 216.33157 e = 0.1736105 Node = 73.50271 (2000.0) a = 4.4860795 AU Inc. = 9.76135 n'= 0.10372982 q = 3.7072490 AU P = 9.502 years The predicted orbit for the 2005 return is as follows: T = 2005 Dec. 19.91158 TT Epoch = 2005 Dec. 16.0 TT Peri. = 222.67081 e = 0.2555934 Node = 58.94091 (2000.0) a = 4.0797308 AU Inc. = 8.70818 n'= 0.11960706 q = 3.0369785 AU P = 8.240 years The following residuals in seconds of arc are from the above orbital elements: Date Code Residual(") Date Code Residual(") Date Code Residual(") 1988/ 960421 867 1.5- 0.2+ 970705 360 0.3+ 0.4- 880810 675 (0.7+ 2.8-) 960421 867 1.7- 0.3+ 970705 360 0.4+ 0.5- 880810 675 1.1- 1.2- 960512 360 0.7- 0.8+ 970713 046 0.1- 0.2+ 880812 675 1.9- 0.9- 960512 360 0.9- 0.7+ 970713 046 0.8- 0.4- 1989/ 960515 691 0.8- 0.3+ 970713 046 0.5- 0.1- 890907 675 0.9- 0.4- 960515 691 0.8- 0.2+ 970713 696 0.8+ 0.1+ 890907 675 0.2+ 0.1+ 960515 691 0.8- 0.2+ 970713 696 0.9+ 0.3+ 890908 675 (3.2- 3.0-) 960522 360 1.1- 0.5+ 970713 696 0.8+ 0.4+ 891002 675 0.6+ 0.3- 960522 360 0.5- 0.3+ 970713 696 0.8+ 0.3+ 891002 675 0.3+ 1.7- 960605 421 0.8- 0.5+ 970713 696 0.8+ 0.1+ 891005 675 (3.2+ 2.8-) 960605 421 0.2- 0.7+ 970728 046 0.1+ 0.4- 891006 675 (0.4+ 5.4-) 960605 421 0.9- 0.5+ 970728 046 0.0 0.0 891006 675 (0.0 4.1-) 960609 400 0.0 0.4+ 970801 360 0.4+ 0.2- 891008 413 0.8+ 0.7+ 960609 400 0.8- 0.8+ 970801 360 0.4+ 0.2- 891010 413 (4.1+ 0.2+) 960611 557 0.1+ 0.1- 970801 360 0.5+ 0.1- 891020 413 1.2+ 0.3- 960611 557 0.3+ 0.5+ 970802 402 0.1+ 0.2- 891023 372 0.7+ 1.2- 960611 557 0.0 0.2+ 970802 402 0.4+ 0.2- 891023 372 0.4+ 0.3+ 960611 557 0.1+ 0.2- 970802 402 0.3+ 0.4- 891025 801 (2.1- 0.1-) 960615 421 0.4+ 1.0+ 970811 402 0.1+ 0.9+ 891026 675 0.0 1.2- 960615 421 0.1- 0.9+ 970811 402 0.3+ 0.8+ 891028 675 0.9- 0.3+ 960616 046 (2.0- 0.7+) 970811 402 0.5+ 0.7+ 891029 801 0.7+ 1.6+ 960616 046 (2.3- 0.9-) 970825 402 0.4- 0.6+ 891029 801 0.7+ 0.3+ 960616 046 1.6- 0.0 970825 402 0.5+ 0.3+ 891031 372 (4.2+ 0.2-) 960616 046 (2.7- 0.1-) 970825 402 0.0 0.0 891129 675 (3.1+ 1.1-) 960617 046 0.6- 0.2+ 970828 867 1.8+ 1.2- 891201 675 (2.6+ 0.2-) 960617 046 0.1+ 0.0 970828 867 (2.0+ 1.0-) 1993/ 960617 046 0.6- 0.4+ 970904 900 0.9- 1.3+ 930124 691 1.2+ 1.7- 960618 691 0.4+ 0.3+ 970904 900 (4.3- 0.6+) 930124 691 1.1+ 1.7- 960618 691 0.2+ 0.4+ 971029 360 1.8+ 1.0- 930124 691 0.8+ 1.0- 960618 691 0.1+ 0.3+ 971029 360 1.7+ 0.7- 930125 691 0.1- 1.5- 960624 709 0.3+ 0.4- 971108 696 1.1+ 1.0- 930125 691 0.6+ 0.9- 960624 709 0.2+ 0.5- 971108 696 1.2+ 1.0- 930125 691 0.1+ 0.4- 960624 709 0.1+ 0.3- 971108 696 1.2+ 1.0- 1995/ 960624 709 0.2+ 0.3- 1998/ 950128 691 0.5- 0.8- 960624 709 0.2+ 0.5- 980822 402 0.4- 0.6- 950128 691 0.1- 1.1- 960624 709 0.3+ 0.4- 980822 402 0.3- 0.6- 950128 691 0.1+ 0.9- 960624 709 0.3+ 0.5- 980822 402 0.1- 0.3- 950129 691 0.3+ 1.3- 960624 709 0.1+ 0.5- 980826 143 0.8- 1.5- 950129 691 0.3+ 1.1- 960624 709 0.1- 0.4- 980826 143 1.4- 0.7- 950129 691 0.6+ 1.1- 960624 709 0.0 0.3- 980919 900 1.3- 0.6- 950201 691 0.8- 1.2- 960624 709 0.0 0.0 980919 900 1.8- 0.3- 950201 691 1.4- 1.4- 960624 709 0.2+ 0.6- 981024 360 0.2+ 0.5+ 950201 691 0.7- 1.5- 960624 709 0.2+ 0.6- 981024 360 0.4+ 0.5+ 950227 360 0.0 0.5- 960624 709 0.0 0.6- 981110 360 0.9+ 0.1- 950227 360 0.5+ 0.5- 960624 709 0.2+ 0.6- 981110 360 0.9+ 0.4- 950402 693 0.6- 0.1- 960624 118 0.3+ 0.1+ 981123 693 0.3+ 0.3- 950402 693 0.5- 0.0 960713 595 0.6+ 0.3+ 981123 693 0.9+ 0.0 950402 693 0.6- 0.0 960713 595 1.6+ 0.6- 981123 693 1.1+ 0.1- 950407 360 0.0 0.5- 960713 595 (2.7+ 1.6-) 981217 360 1.3+ 1.2- 950407 360 0.1+ 0.4- 960715 360 0.5+ 0.1- 981217 360 1.3+ 1.4- 950407 360 0.1+ 0.2- 960715 360 0.4+ 0.1+ 981218 402 (1.2+ 2.2-) 950426 360 0.4- 0.4- 960721 118 1.4+ 1.2- 981218 402 0.9+ 1.9- 950426 360 0.2- 0.1+ 960805 360 1.1+ 0.1- 981218 402 1.0+ 1.4- 950523 360 0.5+ 0.3+ 960805 360 0.8+ 0.5+ 981218 402 1.3+ 1.6- 950523 360 0.5+ 0.1+ 1997/ 1999/ 950526 693 0.3- 0.1- 970515 696 0.5+ 0.0 991010 704 0.7- 0.1+ 950526 693 0.5- 0.5- 970515 696 0.6+ 0.1- 991010 704 0.5- 1.0+ 950623 691 0.7+ 0.3- 970515 696 0.7+ 0.0 991010 704 (2.2- 0.6+) 950623 691 0.6+ 0.6- 970607 402 0.6- 0.0 991015 704 1.3- 0.6- 1996/ 970607 402 0.1- 0.0 991015 704 1.0- 0.6+ 960328 691 1.0- 0.2- 970607 402 0.8- 1.3- 991015 704 (2.4- 0.3-) 960411 360 1.0- 0.2- 970626 402 1.0+ 0.2+ 991015 704 (2.7- 0.6-) 960411 360 1.6- 0.4+ 970626 402 0.0 0.1+ 991104 360 0.8- 0.6+ 960418 557 0.5- 1.0+ 970626 402 0.1- 0.3+ 991104 360 1.3- 0.4+ 960418 557 0.6- 0.6+ 970703 402 0.3- 0.5- 991104 360 1.1- 0.4+ 960419 691 0.1- 0.8+ 970703 402 0.2- 0.2- 991203 360 0.8- 0.1+ 960419 691 0.1+ 0.1+ 970703 402 0.1- 0.4- 991203 360 0.3- 0.0 960421 867 (2.0- 0.5+) 970704 402 0.4+ 0.2- 991212 897 0.1- 0.4- 960421 360 0.4- 0.0 970704 402 0.4+ 0.1- 991212 897 1.1- 0.1- 960421 360 0.7- 0.1+ 970704 402 0.3+ 0.3- ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 2000 Dec. 20