OAA computing section circular NK 1184 161P/Hartley-IRAS
The following improved orbital elements, by S. Nakano, are from 125 observations 1983-2005, including planetary perturbations by Mercury to Neptune and three minor planets, Ceres, Pallas, Vesta, and non-gravitational effect of style II. The mean residual is +/- 1.13 arc seconds. See previous orbits in NK 845 and NK 1122R (= HICQ 2005). Epoch = 2005 July 9.0 TT T = 2005 June 20.85209 +/- 0.00047 (m.e.) TT Peri. = 47.08305 +/- 0.00044 Node = 1.39624 +/- 0.00008 (2000.0) Inc. = 95.69883 +/- 0.00007 q = 1.2750822 +/- 0.0000021 AU e = 0.8348377 +/- 0.0000069 a = 7.7201765 +/- 0.0000415 AU n' = 0.04594764 +/- 0.00000037 P = 21.451 +/- 0.0001730 years (+/- 0.06 day) A1 = -0.204 +/- 0.148 A2 = -2.97535 +/- 0.09089 T = 1984 Jan. 8.71346 TT Epoch = 1984 Jan. 21.0 TT Peri. = 47.11846 e = 0.8339941 Node = 1.49762 (2000.0) a = 7.7255548 AU Inc. = 95.73258 n'= 0.04589967 q = 1.2824876 AU P = 21.473 years The predicted orbit for the 2026 return is as follows: T = 2026 Oct. 29.79473 TT Epoch = 2026 Nov. 16.0 TT Peri. = 47.07867 e = 0.8355351 Node = 1.47749 (2000.0) a = 7.6922268 AU Inc. = 95.79265 n'= 0.04619830 q = 1.2651010 AU P = 21.334 years The following residuals in seconds of arc are from the above orbital elements: Date Code Residual(") Date Code Residual(") Date Code Residual(") 1983/ 840329 114 0.3- 2.5+ 2005/ 831104 413 (4.3- 8.1-) 840330 657 (3.9+ 0.6-) 050102 415 (2.5+ 0.9+) 831104 413 (5.4- 8.4-) 840331 114 (3.5+ 1.7+) 050102 I77 (1.7+ 2.6-) 831123 413 2.1- 0.2+ 840401 136 (0.4+ 9.0+) 050102 I77 0.3- 0.6- 831123 413 (1.3- 3.8-) 840401 136 1.0- 1.7+ 050111 415 (2.0+ 0.4+) 831127 675 0.7- 0.3+ 840401 136 0.3- 2.1+ 050111 415 (2.0+ 0.7-) 831128 675 (3.6+ 11.5-) 840402 657 0.6- 0.0 050112 415 (3.2+ 0.3+) 831130 688 2.0+ 0.6- 840402 114 1.4+ 2.4+ 050113 415 (2.3+ 0.4-) 831130 657 (3.6+ 6.5+) 840403 114 (2.0- 4.0+) 050512 427 (2.2+ 1.8+) 831130 688 0.2- 1.2- 840405 491 1.1+ 0.1+ 050512 427 0.1+ 1.1- 831201 657 0.1+ 1.8- 840406 491 1.8+ 0.5+ 050515 349 0.1+ 1.1- 831201 801 2.1- 0.7- 840406 168 (3.6+ 0.5+) 050515 349 0.6+ 0.5- 831203 046 1.9- 1.8+ 840407 168 (4.5+ 2.8-) 050516 349 1.2+ 0.6+ 831203 046 (1.6- 4.8-) 840408 675 (3.5- 12.7+) 050516 349 1.5+ 1.3+ 831204 657 (3.8+ 1.1+) 840413 657 2.3- 2.4+ 050516 349 1.6+ 0.9+ 831204 046 1.3- 0.6+ 840417 168 0.5- 0.9- 050525 349 0.6+ 0.3+ 831204 046 (1.4+ 6.8-) 840417 168 0.6- 2.0+ 050525 349 0.4+ 0.0 831205 688 0.1- 2.1- 840418 168 2.8+ 0.7+ 050525 349 0.9+ 0.6+ 831205 688 0.9+ 2.3- 840418 168 (5.1+ 1.1+) 050527 349 0.1- 0.3- 831207 046 0.4- 0.5+ 840418 168 0.7+ 1.6+ 050527 349 0.2+ 0.1- 831207 046 2.1+ 0.4- 840420 675 0.1- 2.1+ 050527 349 0.6+ 0.2+ 831208 707 1.0+ 1.2+ 840420 102 (4.1- 1.8+) 050531 349 0.3- 0.8+ 831208 413 (3.5- 1.7+) 840421 675 0.9+ 2.2+ 050531 349 0.1- 0.7+ 831208 413 (4.1+ 3.1-) 840422 168 (1.5+ 4.5+) 050531 349 0.2- 0.5+ 831208 801 1.1- 0.5+ 840423 168 (4.4+ 6.5+) 050604 J76 0.6+ 0.8+ 831225 984 (3.5+ 4.4+) 840425 657 1.4- 1.1- 050604 J76 0.0 0.8+ 831229 688 1.5+ 0.5+ 840426 657 0.2+ 1.2- 050604 J76 1.0- 0.7+ 831229 688 (4.6+ 1.9+) 840427 657 (6.2- 0.7-) 050605 213 0.2+ 1.1+ 1984/ 840428 801 0.4- 3.2- 050605 213 0.4+ 0.3- 840101 801 2.3+ 2.0+ 840503 168 2.0+ 2.2- 050605 213 0.2+ 0.4- 840104 502 (5.0+ 1.2-) 840525 095 2.0- 1.2+ 050605 349 0.6- 0.9+ 840107 801 1.1+ 1.6+ 840528 095 2.6+ 2.7- 050605 349 0.4- 1.0+ 840109 801 0.8+ 1.2+ 840604 801 0.2- 0.4- 050605 349 0.0 0.8+ 840211 675 (3.8+ 1.6+) 2004/ 050609 J76 0.4- 1.3- 840225 168 2.1+ 2.1+ 041103 413 0.1+ 0.0 050609 J76 0.7- 0.4- 840225 168 2.0+ 1.2+ 041103 413 0.0 0.3- 050609 J76 0.4- 0.6- 840226 168 1.5+ 1.4+ 041103 413 0.1+ 0.2+ 050611 349 0.9- 0.3- 840226 168 (1.4+ 3.8+) 041105 474 0.4+ 0.3+ 050611 349 1.0- 0.5- 840227 114 (1.0+ 3.5+) 041105 474 0.3+ 0.3- 050611 349 0.8- 0.5+ 840301 168 (8.3+ 7.9+) 041105 474 0.1+ 0.3- 050613 349 0.2- 0.1+ 840302 168 (2.7+ 4.4+) 041105 474 0.1- 1.4+ 050613 349 0.6- 0.5+ 840302 372 (5.1+ 3.2+) 041105 413 0.1- 0.5+ 050613 349 0.5- 0.5+ 840303 168 (4.9+ 3.9+) 041106 415 0.0 0.2+ 050618 J76 0.7- 0.5- 840303 168 (4.4+ 4.2+) 041106 415 0.8+ 1.0+ 050618 J76 0.8- 0.3- 840304 168 (4.3+ 0.6+) 041106 415 0.3+ 0.3+ 050618 J76 1.1- 0.2- 840304 168 (4.2+ 2.4-) 041106 415 0.1+ 0.0 050618 213 1.5- 0.1+ 840304 168 (3.1+ 4.5+) 041106 415 0.7+ 0.5- 050618 213 1.6- 0.1+ 840304 372 (4.8+ 3.1+) 041107 E12 0.3+ 0.1+ 050618 213 1.3- 0.2- 840308 168 (7.9+ 0.1+) 041107 E12 0.7- 1.1+ 050618 232 1.7- 0.1- 840309 168 2.7+ 3.2+ 041107 E12 0.5+ 1.2+ 050618 232 1.6- 0.1+ 840311 675 (4.0+ 0.8+) 041107 E12 1.0+ 1.0+ 050618 232 1.5- 0.1+ 840321 102 (9.9+ 5.5-) 041112 415 0.1+ 0.4- 050619 A11 1.0+ 0.1+ 840322 168 (1.7+ 4.4+) 041112 415 0.1+ 0.5- 050619 A11 (3.7- 4.0+) 840327 114 (1.1+ 3.5+) 041117 415 1.6+ 0.9+ 050619 A11 0.0 0.9+ 840327 114 (0.4+ 5.1+) 041117 415 0.4+ 0.2- 050619 A11 0.0 0.3- 840328 136 1.3+ 3.1- 041218 415 1.5+ 0.2- 050619 A11 0.6- 0.6+ 840328 801 (3.6+ 0.6-) 041218 415 1.8+ 0.1- 050619 A11 1.7- 0.5- 840328 381 (4.1+ 1.2+) 041220 415 0.7+ 0.1- 050619 J76 0.7- 0.2- 840329 168 0.7- 0.8- 041220 415 1.8+ 1.0+ 050619 J76 1.0- 0.7- 840329 168 0.1- 2.0+ 041230 415 1.7+ 0.6- 050619 J76 1.2- 0.6- 840329 168 1.1+ 2.1- 041230 415 1.3+ 0.4- ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 2005 June 21