OAA computing section circular NK 1280 170P/Christensen
The following improved orbital elements, by S. Nakano, are from 89 observations 1997 to 2005. 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. See an orbit in NK 1216. Epoch = 2006 Jan. 25.0 TT T = 2006 Jan. 26.70505 +/- 0.01499 (m.e.) TT Peri. = 225.43591 +/- 0.00389 Node = 143.03536 +/- 0.00013 (2000.0) Inc. = 10.12605 +/- 0.00011 q = 2.9299404 +/- 0.0000434 AU e = 0.3037577 +/- 0.0000093 a = 4.2082197 +/- 0.0000199 AU n' = 0.11417117 +/- 0.00000081 P = 8.633 +/- 0.0000613 years T = 1997 June 20.76146 TT Epoch = 1997 June 1.0 TT Peri. = 225.41508 e = 0.3058212 Node = 143.06240 (2000.0) a = 4.1915808 AU Inc. = 10.13977 n'= 0.11485167 q = 2.9097065 AU P = 8.582 years The predicted orbit for the 2014 return is as follows: T = 2014 Sept.18.15812 TT Epoch = 2014 Sept.20.0 TT Peri. = 225.83816 e = 0.3046008 Node = 142.91990 (2000.0) a = 4.1999078 AU Inc. = 10.12845 n'= 0.11451027 q = 2.9206127 AU P = 8.607 years The following residuals in seconds of arc are from the above orbital elements: Date Code Residual(") Date Code Residual(") Date Code Residual(") 1997/ 050804 644 0.1+ 0.4- 050829 699 0.7- 1.3- 971031 566 1.0- 0.3- 050805 644 0.1+ 0.0 050829 699 0.1- 0.4- 971031 566 0.3+ 0.1+ 050805 644 0.0 0.0 050829 615 0.5- 0.8- 971031 566 0.8+ 1.2- 050805 644 0.2+ 0.4- 050829 615 0.2- 1.3- 971130 566 0.3+ 1.3- 050806 644 0.1+ 0.2+ 050829 615 0.1+ 0.5+ 971227 566 0.5+ 0.8- 050806 644 0.6+ 0.4- 050830 615 0.2- 0.5- 2005/ 050806 644 0.1+ 0.2- 050830 615 0.3- 0.2- 050617 G96 0.6- 0.9- 050808 D74 0.2- 0.1+ 050830 615 0.7- 0.2+ 050617 G96 0.5- 0.8- 050808 D74 0.9- 0.5+ 050905 703 0.1- 1.1+ 050617 G96 0.1- 0.9- 050808 D74 0.4- 0.8+ 050905 703 (3.1- 0.4-) 050617 G96 0.1+ 1.2- 050808 A79 (4.1- 2.7-) 050905 703 1.8- 0.1+ 050618 734 0.6- 0.2- 050809 A79 (3.0- 8.2-) 050905 703 0.1- 1.0- 050618 734 0.3- 1.6- 050811 673 0.2- 0.1- 050905 215 0.9- 0.5- 050618 734 (2.8- 2.2-) 050811 673 0.3+ 0.0 050906 415 0.3+ 0.1- 050618 G96 0.1+ 0.2- 050811 673 0.4+ 0.2+ 050906 415 1.0+ 0.1+ 050618 G96 0.3+ 0.5- 050811 673 0.3+ 0.1+ 050909 D83 0.2- 0.5+ 050618 G96 0.6+ 0.1- 050817 673 0.2- 0.0 050909 D83 0.8- 0.0 050618 G96 0.7+ 0.2- 050817 673 0.0 0.7+ 050909 D83 1.1- 0.3+ 050619 474 1.2- 0.6- 050817 673 1.4- 0.1+ 050929 415 0.7+ 0.8+ 050619 474 0.8- 0.9- 050817 673 1.2+ 0.6+ 050929 415 1.0+ 0.5+ 050619 474 1.6- 1.3- 050825 213 0.6- 1.5+ 050930 G96 0.5+ 0.7+ 050619 474 (0.4- 2.2-) 050825 213 0.3- 1.3+ 050930 699 0.5+ 0.4- 050630 G96 0.3- 0.7- 050825 213 0.6- 0.6+ 050930 G96 0.7+ 0.7+ 050630 G96 0.6- 0.8- 050827 644 0.1+ 0.2+ 050930 G96 0.6+ 0.6+ 050703 413 0.1+ 0.6- 050827 644 0.3+ 0.1+ 050930 699 0.8+ 0.1+ 050703 413 0.2- 0.4- 050827 644 0.3+ 0.1- 050930 699 0.6+ 1.5+ 050704 413 0.1- 0.8- 050829 704 0.2- 0.2+ 050930 699 1.6+ 1.0+ 050704 413 0.1- 0.8- 050829 704 1.2+ 0.5+ 050930 415 0.5+ 0.8+ 050726 213 0.5+ 0.6- 050829 704 0.7+ 0.6+ 050930 213 0.4+ 1.5+ 050727 213 0.0 0.2- 050829 704 (0.4- 3.2+) 050930 213 0.6+ 1.2+ 050727 213 0.4- 0.4+ 050829 704 1.4+ 0.1+ 050930 213 0.8+ 1.2+ 050804 644 0.5+ 0.1+ 050829 699 0.7- 0.0 050804 644 0.1+ 0.1- 050829 699 0.5- 0.9- ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 2005 Oct. 29