OAA computing section circular NK 855 117P/Helin-Roman-Alu 1
The following improved orbital elements, by S. Nakano, are from 191 observations 1988 to 1999. Perturbations by Mercury to Neptune and three minor planets, Ceres, Pallas and Vesta, were taken into account. The mean residual is +/- 0.74 arc second. See an orbit in NK 745. Epoch = 1997 Mar. 13.0 TT T = 1997 Mar. 26.87483 +/- 0.00058 (m.e.) TT Peri. = 215.07737 +/- 0.00012 Node = 73.47239 +/- 0.00009 (2000.0) Inc. = 9.74247 +/- 0.00002 q = 3.7148319 +/- 0.0000006 AU e = 0.1756998 +/- 0.0000001 a = 4.5066493 +/- 0.0000002 AU n' = 0.10302045 +/- 0.00000001 P = 9.567 +/- 0.0000007 years T = 1987 Oct. 12.39118 TT Epoch = 1987 Oct. 12.0 TT Peri. = 216.33145 e = 0.1736104 Node = 73.50262 (2000.0) a = 4.4860807 AU Inc. = 9.76134 n'= 0.10372978 q = 3.7072503 AU P = 9.502 years The predicted orbit for the 2005 return is as follows: T = 2005 Dec. 19.90714 TT Epoch = 2005 Dec. 16.0 TT Peri. = 222.67096 e = 0.2555944 Node = 58.94037 (2000.0) a = 4.0797274 AU Inc. = 8.70812 n'= 0.11960721 q = 3.0369721 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/ 960515 691 0.8- 0.3+ 970728 046 0.1+ 0.4- 880810 675 (0.0 3.2-) 960515 691 0.8- 0.3+ 970728 046 0.0 0.0 880810 675 1.8- 1.6- 960522 360 1.1- 0.6+ 970801 360 0.4+ 0.2- 880812 675 (2.6- 1.2-) 960522 360 0.5- 0.4+ 970801 360 0.4+ 0.2- 1989/ 960605 421 0.9- 0.6+ 970801 360 0.6+ 0.1- 890907 675 1.0- 0.5- 960605 421 0.2- 0.8+ 970802 402 0.2+ 0.2- 890907 675 0.1+ 0.1- 960605 421 0.9- 0.6+ 970802 402 0.4+ 0.2- 890908 675 (3.3- 3.1-) 960609 400 0.1- 0.5+ 970802 402 0.3+ 0.4- 891002 675 0.4+ 0.5- 960609 400 0.8- 0.8+ 970811 402 0.1+ 0.9+ 891002 675 0.1+ 1.9- 960611 557 0.1+ 0.0 970811 402 0.3+ 0.8+ 891005 675 (3.1+ 3.0-) 960611 557 0.2+ 0.6+ 970811 402 0.5+ 0.7+ 891006 675 (0.2+ 5.5-) 960611 557 0.0 0.3+ 970825 402 0.4- 0.6+ 891006 675 (0.1- 4.3-) 960611 557 0.1+ 0.1- 970825 402 0.5+ 0.3+ 891008 413 0.7+ 0.5+ 960615 421 0.4+ 1.1+ 970825 402 0.0 0.0 891010 413 (3.9+ 0.0 ) 960615 421 0.1- 1.0+ 970828 867 1.8+ 1.2- 891020 413 1.0+ 0.5- 960616 046 (2.0- 0.8+) 970828 867 (2.0+ 1.0-) 891023 372 0.6+ 1.3- 960616 046 (2.4- 0.8-) 970904 900 0.9- 1.2+ 891023 372 0.3+ 0.1+ 960616 046 1.6- 0.1+ 970904 900 (4.3- 0.6+) 891025 801 (2.3- 0.3-) 960616 046 (2.7- 0.0 ) 971029 360 1.8+ 1.1- 891026 675 0.2- 1.4- 960617 046 0.6- 0.2+ 971029 360 1.7+ 0.7- 891028 675 1.1- 0.1+ 960617 046 0.1+ 0.1+ 971108 696 1.1+ 1.0- 891029 801 0.5+ 1.4+ 960617 046 0.6- 0.5+ 971108 696 1.2+ 1.0- 891029 801 0.5+ 0.1+ 960618 691 0.4+ 0.4+ 971108 696 1.2+ 1.0- 891031 372 (4.1+ 0.4-) 960618 691 0.1+ 0.4+ 1998/ 891129 675 (3.0+ 1.3-) 960618 691 0.0 0.4+ 980822 402 0.1- 0.5- 891201 675 (2.4+ 0.3-) 960624 709 0.3+ 0.4- 980822 402 0.0 0.5- 1993/ 960624 709 0.2+ 0.4- 980822 402 0.2+ 0.2- 930124 691 1.4+ 1.7- 960624 709 0.1+ 0.2- 980826 143 0.5- 1.4- 930124 691 1.3+ 1.7- 960624 709 0.2+ 0.2- 980826 143 1.1- 0.6- 930124 691 1.0+ 1.0- 960624 709 0.2+ 0.4- 980919 900 1.0- 0.5- 930125 691 0.1+ 1.6- 960624 709 0.2+ 0.3- 980919 900 1.5- 0.3- 930125 691 0.9+ 0.9- 960624 709 0.3+ 0.4- 980924 699 (2.4- 1.0-) 930125 691 0.3+ 0.5- 960624 709 0.0 0.4- 980924 699 (2.2- 0.4-) 1995/ 960624 709 0.1- 0.3- 980924 699 1.6- 0.6- 950128 691 0.4- 0.8- 960624 709 0.0 0.2- 981024 360 0.5+ 0.6+ 950128 691 0.0 1.1- 960624 709 0.0 0.1+ 981024 360 0.7+ 0.6+ 950128 691 0.2+ 0.9- 960624 709 0.2+ 0.5- 981110 360 1.2+ 0.0 950129 691 0.4+ 1.2- 960624 709 0.2+ 0.5- 981110 360 1.2+ 0.3- 950129 691 0.4+ 1.1- 960624 709 0.0 0.5- 981123 693 0.6+ 0.2- 950129 691 0.7+ 1.1- 960624 709 0.1+ 0.6- 981123 693 1.2+ 0.1+ 950201 691 0.7- 1.1- 960624 118 0.3+ 0.2+ 981123 693 1.4+ 0.1- 950201 691 1.3- 1.4- 960713 595 0.6+ 0.3+ 981217 360 1.5+ 1.2- 950201 691 0.6- 1.5- 960713 595 1.6+ 0.5- 981217 360 1.5+ 1.4- 950227 360 0.1+ 0.4- 960713 595 (2.6+ 1.5-) 981218 402 (1.4+ 2.2-) 950227 360 0.6+ 0.5- 960715 360 0.5+ 0.0 981218 402 1.1+ 1.8- 950402 693 0.5- 0.0 960715 360 0.4+ 0.2+ 981218 402 1.3+ 1.4- 950402 693 0.4- 0.0 960721 118 1.3+ 1.1- 981218 402 1.5+ 1.5- 950402 693 0.5- 0.0 960805 360 1.0+ 0.0 1999/ 950407 360 0.1+ 0.5- 960805 360 0.8+ 0.6+ 991010 704 0.2- 0.2+ 950407 360 0.2+ 0.4- 1997/ 991010 704 0.0 1.1+ 950407 360 0.2+ 0.2- 970515 696 0.5+ 0.0 991010 704 1.7- 0.7+ 950426 360 0.3- 0.4- 970515 696 0.6+ 0.1- 991015 704 0.8- 0.4- 950426 360 0.1- 0.1+ 970515 696 0.7+ 0.0 991015 704 0.5- 0.8+ 950523 360 0.6+ 0.4+ 970607 402 0.6- 0.1+ 991015 704 1.9- 0.1- 950523 360 0.6+ 0.2+ 970607 402 0.1- 0.0 991015 704 (2.2- 0.4-) 950526 693 0.2- 0.0 970607 402 0.8- 1.3- 991020 704 0.0 0.0 950526 693 0.4- 0.5- 970626 402 1.0+ 0.2+ 991020 704 0.3- 0.5+ 950623 691 0.8+ 0.3- 970626 402 0.0 0.1+ 991020 704 (0.9- 2.0+) 950623 691 0.7+ 0.6- 970626 402 0.1- 0.3+ 991020 704 0.7- 1.9+ 1996/ 970703 402 0.3- 0.5- 991104 360 0.3- 0.7+ 960328 691 1.0- 0.1- 970703 402 0.2- 0.2- 991104 360 0.8- 0.6+ 960411 360 1.0- 0.1- 970703 402 0.1- 0.3- 991104 360 0.6- 0.5+ 960411 360 1.7- 0.5+ 970704 402 0.4+ 0.2- 991105 704 0.5- 0.1- 960418 557 0.6- 1.1+ 970704 402 0.4+ 0.1- 991105 704 (2.0- 0.2+) 960418 557 0.6- 0.7+ 970704 402 0.3+ 0.3- 991105 704 1.2- 0.7+ 960419 691 0.1- 0.9+ 970705 360 0.3+ 0.4- 991105 704 1.2- 0.5+ 960419 691 0.1+ 0.2+ 970705 360 0.4+ 0.5- 991105 704 0.7- 1.0+ 960421 867 (2.0- 0.6+) 970713 046 0.1- 0.2+ 991203 360 0.3- 0.2+ 960421 360 0.4- 0.1+ 970713 046 0.8- 0.4- 991203 360 0.2+ 0.2+ 960421 360 0.7- 0.1+ 970713 046 0.5- 0.1- 991208 699 0.8- 0.4- 960421 867 1.5- 0.3+ 970713 696 0.8+ 0.1+ 991208 699 (2.5- 0.0 ) 960421 867 1.8- 0.4+ 970713 696 0.9+ 0.3+ 991208 699 1.9- 0.2- 960512 360 0.7- 0.9+ 970713 696 0.8+ 0.4+ 991212 897 0.4+ 0.3- 960512 360 0.9- 0.8+ 970713 696 0.8+ 0.3+ 991212 897 0.6- 0.1+ 960515 691 0.8- 0.4+ 970713 696 0.8+ 0.1+ ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 2002 May 8