OAA computing section circular NK 1131 P/2004 Y1 (Christensen)
The following improved orbital elements, by S. Nakano, are from 51 observations 1998 to 2004. Perturbations by Mercury to Neptune and three minor planets, Ceres, Pallas and Vesta, were taken into account. The mean residual is +/- 0.80 arc second. The comet will be numbered as 164P. Note A917 OA is located near the predicted position. Epoch = 2004 June 4.0 TT T = 2004 June 21.89335 +/- 0.00163 (m.e.) TT Peri. = 325.45233 +/- 0.00102 Node = 88.68929 +/- 0.00062 (2000.0) Inc. = 16.24191 +/- 0.00016 q = 1.6457462 +/- 0.0000304 AU e = 0.5464251 +/- 0.0000084 a = 3.6283890 +/- 0.0000262 AU n' = 0.14260453 +/- 0.00000154 P = 6.911 +/- 0.0000749 years T = 1997 July 22.17976 TT Epoch = 1997 July 11.0 TT Peri. = 325.29559 e = 0.5468615 Node = 88.76634 (2000.0) a = 3.6251723 AU Inc. = 16.24137 n'= 0.14279437 q = 1.6427052 AU P = 6.902 years The predicted orbit for the 2011 return is as follows: T = 2011 June 2.34072 TT Epoch = 2011 June 8.0 TT Peri. = 325.85033 e = 0.5414035 Node = 88.32665 (2000.0) a = 3.6531811 AU Inc. = 16.26048 n'= 0.14115533 q = 1.6753360 AU P = 6.982 years The following residuals in seconds of arc are from the above orbital elements: Date Code Residual(") Date Code Residual(") Date Code Residual(") 1998/ 041119 704 0.2+ 0.0 041222 673 1.8+ 1.1+ 980124 566 0.0 1.0- 041209 704 0.3+ 0.3- 041222 673 1.6+ 0.8+ 980124 566 0.3- 0.8- 041209 704 0.8- 0.1+ 041222 673 1.2+ 0.4+ 980124 566 0.1- 1.0- 041209 704 0.8- 0.3+ 041222 703 1.1- 0.2- 980418 699 0.3+ 0.1+ 041209 704 0.3+ 0.2- 041222 673 1.5+ 0.7+ 980418 699 0.4- 0.0 041209 704 (2.2+ 2.8+) 041222 703 1.2- 0.2+ 980418 699 0.7- 0.7- 041215 704 0.1+ 0.0 041222 703 1.2- 0.0 2004/ 041215 704 0.5- 0.6- 041222 703 1.5- 0.6- 041019 704 0.2- 0.2- 041215 704 0.5+ 0.0 041223 D83 1.6- 0.2+ 041019 704 0.5+ 0.8- 041215 704 0.4+ 0.5+ 041223 D83 1.5+ 0.1- 041019 704 0.4+ 0.4- 041215 704 0.3- 1.0+ 041223 D83 0.5+ 0.2- 041021 704 0.8+ 0.2+ 041221 703 0.5- 0.1- 041223 D83 0.9+ 1.3- 041021 704 0.7- 0.1- 041221 703 1.0- 0.4- 041223 349 0.8- 0.2- 041021 704 0.7+ 0.7+ 041221 703 0.9- 0.4- 041223 349 0.5- 0.1+ 041021 704 0.8- 0.2+ 041221 703 1.8- 0.6- 041223 349 0.3- 0.2+ 041021 704 1.5- 0.1+ 041222 673 1.7+ 1.6+ 041224 A61 0.2+ 0.8+ 041119 704 0.4- 0.8- 041222 673 1.7+ 1.3+ 041224 A61 0.3+ 0.5- 041119 704 0.2+ 0.4- 041222 673 1.5+ 1.5+ 041224 A61 0.8+ 0.4- ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 2004 Dec. 26