Nakano Note (Nakano wa Kangaeru noda) NK 1769 C/2001 D1 = 2004 X7 = 2008 S2 (SOHO)
The following improved orbital elements, by S. Nakano, are from 56 observations 2001 to 2008. Perturbations by Mercury to Neptune and three minor planets, Ceres, Pallas and Vesta, were taken into account. The mean residual is +/- 8.42 arc seconds. Epoch = 2008 Sept.11.0 TT T = 2008 Sept.17.95684 +/- 0.00017 (m.e.) TT Peri. = 172.43217 +/- 0.03293 Node = 165.25371 +/- 0.02659 (2000.0) Inc. = 19.85934 +/- 0.01328 q = 0.0465596 +/- 0.0000248 AU e = 0.9808096 +/- 0.0000102 a = 2.4261935 +/- 0.0007533 AU n' = 0.26080501 +/- 0.00012146 P = 3.779 +/- 0.0017601 years (+/- 0.64 day) [ T = 1997 May 1.67565 TT Epoch = 1997 Apr. 22.0 TT Peri. = 172.05132 e = 0.9797709 Node = 165.57754 (2000.0) a = 2.4351742 AU Inc. = 18.85224 n'= 0.25936359 q = 0.0492613 AU P = 3.800 years ] T = 2001 Feb. 18.76912 TT Epoch = 2001 Feb. 20.0 TT Peri. = 172.04580 e = 0.9796106 Node = 165.57823 (2000.0) a = 2.4363495 AU Inc. = 18.79918 n'= 0.25917594 q = 0.0496757 AU P = 3.803 years T = 2004 Dec. 7.82053 TT Epoch = 2004 Dec. 21.0 TT Peri. = 172.40325 e = 0.9807132 Node = 165.26697 (2000.0) a = 2.4267131 AU Inc. = 19.78682 n'= 0.26072124 q = 0.0468035 AU P = 3.780 years The predicted orbit for the 2012 return is as follows: T = 2012 June 30.49423 TT Epoch = 2012 July 12.0 TT Peri. = 172.43606 e = 0.9806889 Node = 165.24162 (2000.0) a = 2.4272197 AU Inc. = 19.83452 n'= 0.26063962 q = 0.0468722 AU P = 3.781 years The following residuals in seconds of arc are from the above orbital elements: Date Code Residual(") Date Code Residual(") Date Code Residual(") 2001/ 010218 249 0.9- 1.1+ Y 041207 249 9.6- 2.1+ Y 010218 249 (4.2+ 28.0+)Y 010218 249(22.0- 4.9-)Y 041207 249 4.0+ 2.2- Y 010218 249(21.0+ 3.0-)Y 010218 249(27.6- 8.9-)Y 041207 249 0.9+ 11.3+ Y 010218 249(21.5+ 15.0+)Y 010218 249 14.1- 2.9- Y 041207 249 10.5+ 4.0- Y 010218 249(14.7+ 26.0-)Y 010218 249(24.0- 1.2+)Y 041207 249 14.4- 0.4+ Y 010218 249(13.3+ 22.0-)Y 010218 249 16.1- 3.3+ Y 041207 249 3.6+ 5.8- Y 010218 249 13.1+ 15.0- Y 010218 249 7.5- 2.6- Y 041207 249 6.2- 6.2+ Y 010218 249 5.4+ 7.9- Y 010218 249(37.3- 0.6+)Y 041207 249 3.0- 2.3+ Y 010218 249 8.0+ 3.2+ Y 010218 249 17.6- 8.1- Y 2008/ 010218 249 2.7+ 7.7- Y 010218 249 13.5- 8.9- Y 080917 249 11.1+ 11.0- Y 010218 249 15.3+ 12.4+ Y 010218 249 15.4- 7.5+ Y 080917 249 17.8- 4.1- Y 010218 249 6.1+ 0.5+ Y 010218 249(24.5- 10.7+)Y 080917 249(12.7+ 27.6+)Y 010218 249 3.7+ 1.4- Y 010218 249 7.7- 7.7- Y 080917 249 17.0+ 8.5- Y 010218 249 14.8+ 5.8+ Y 010218 249(35.2- 0.5-)Y 080917 249 17.7+ 0.6- Y 010218 249 11.9+ 16.9+ Y 010218 249 5.9- 6.2+ Y 080917 249 3.8- 4.2- Y 010218 249 1.5+ 3.1+ Y 010219 249(26.0- 2.2-)Y 080917 249 10.7- 5.3+ Y 010218 249 3.2+ 2.3+ Y 2004/ 080917 249 18.8+ 14.4+ Y 010218 249 10.7- 6.4- Y 041207 249(70.6- 43.4-)Y 080918 249(26.4- 10.4+)Y 010218 249 6.6- 3.8+ Y 041207 249 0.3+ 3.8+ Y 080918 249 3.8- 0.6- Y 010218 249 9.9+ 9.1+ Y 041207 249(23.5- 10.6-)Y 080918 249 1.6- 7.0+ Y 010218 249 4.6+ 1.3+ Y 041207 249 3.1+ 7.9- Y 080918 249 9.6- 11.7+ Y 010218 249 16.1+ 3.7+ Y 041207 249 4.2- 5.4- Y 080918 249 9.6- 8.6- Y 010218 249 2.5- 0.1- Y 041207 249 9.2+ 5.8+ Y 080918 249 1.1+ 3.1- Y 010218 249 1.1+ 2.7- Y 041207 249 3.2+ 6.8+ Y 080918 249 2.8+ 5.2+ Y 010218 249 1.7+ 1.4- Y 041207 249 8.3+ 0.5+ Y 080918 249 10.3- 9.8+ Y ( ) -------- Rejected Obs.
Managing Director of the Oriental Astronomical Association Late edition Syuichi Nakano 2008 Sept. 30