OAA computing section circular NK 1660 C/1997 G2 (Montani)
The following improved orbital elements, by S. Nakano, are from 181 observations 1997 Apr. 12 to 1998 Oct. 18. Perturbations by Mercury to Neptune and three minor planets, Ceres, Pallas and Vesta, were taken into account. The mean residual is +/- 0.77 arc second. The comet has passed 2.90 AU from Jupiter on 2000 Feb. 21 and 1.89 AU from Saturn on 2001 Jan. 28 UT. See an orbit on MPC 30428. Epoch = 1998 Apr. 17.0 TT T = 1998 Apr. 16.34647 +/- 0.00103 (m.e.) TT Peri. = 239.85590 +/- 0.00021 Node = 55.80386 +/- 0.00002 (2000.0) Inc. = 69.83900 +/- 0.00005 q = 3.0847539 +/- 0.0000056 AU e = 0.9941929 +/- 0.0000097 1/a = +0.0018825 +/- 0.0000031 1/AU origin = +0.002518 (Q= 7) future = +0.002676 The following residuals in seconds of arc are from the above orbital elements: Date Code Residual(") Date Code Residual(") Date Code Residual(") 1997/ 970506 402 0.3+ 0.1- 970610 046 0.0 1.2- 970412 691 0.4- 0.8+ 970509 402 1.1+ 0.6+ 970610 046 0.1+ 0.8- 970412 691 0.6- 1.0+ 970509 402 0.7+ 0.6+ 970610 046 0.0 0.8- 970412 691 0.5- 0.1+ 970509 402 0.8+ 1.3+ 970611 118 1.1+ 0.1- 970413 691 0.6- 1.9+ 970509 360 0.2+ 0.2- 970611 118 0.3+ 0.8- 970413 691 0.5- 1.0+ 970509 360 0.1+ 0.2- 970612 402 0.3- 1.3- 970413 691 0.9- 1.0+ 970509 360 0.5+ 0.5+ 970612 402 0.7- 0.8- 970413 691 0.9- 0.3+ 970509 864 0.3- 0.5- 970612 402 1.6- 1.4- 970413 691 0.6- 0.6+ 970509 864 0.0 0.0 970612 360 0.5- 0.6- 970413 691 1.0- 0.8+ 970509 864 0.4+ 0.8+ 970612 360 0.4- 0.8- 970414 691 0.6- 0.5- 970513 691 0.2+ 0.9+ 970613 861 1.0+ 0.8- 970414 691 0.4- 0.5- 970513 691 0.1+ 0.3+ 970613 861 1.3+ 1.0- 970415 867 0.5- 0.3- 970514 557 0.6- 0.3- 970613 861 1.1+ 0.3- 970415 867 0.0 0.6+ 970514 557 0.1+ 0.0 970613 867 0.1+ 0.2+ 970415 867 0.6- 0.1+ 970514 557 0.7+ 0.0 970613 867 0.3- 0.1+ 970415 327 0.4+ 0.4- 970515 118 0.4- 0.0 970623 402 0.6- 0.7+ 970415 327 0.1+ 0.5- 970515 118 0.3- 0.2- 970623 402 0.1- 0.6- 970415 327 0.4+ 0.5+ 970515 118 0.1+ 0.4- 970623 402 0.1+ 0.8+ 970415 327 0.5+ 0.4- 970516 118 0.0 0.8- 970627 118 1.0+ 1.5+ 970416 402 0.8- 0.2- 970516 118 0.0 0.4- 970627 118 1.5+ 1.1+ 970416 402 0.4- 0.6- 970517 402 0.2- 0.2- 970627 118 1.7+ 1.5+ 970416 402 0.1- 0.5+ 970517 402 0.1+ 0.1- 970629 402 0.8- 0.6+ 970416 864 0.0 0.1+ 970517 402 0.3- 0.2- 970629 402 0.9- 0.3- 970416 864 0.3- 0.0 970517 046 0.1- 0.4+ 970629 402 0.6- 0.8+ 970416 864 0.4- 0.0 970517 046 0.6+ 0.3+ 970629 360 0.8- 0.5+ 970416 327 0.1- 0.2- 970517 046 0.1+ 0.3+ 970629 867 1.7+ 0.3+ 970416 327 0.1+ 0.5+ 970527 360 0.0 0.2- 970629 360 0.2- 0.3+ 970416 327 0.2+ 0.3+ 970527 360 0.0 0.3- 970629 867 1.9+ 0.5+ 970416 327 0.1+ 0.1- 970528 897 0.8+ 0.2+ 970723 360 0.4- 0.4+ 970419 658 1.2- 1.2- 970528 897 0.8+ 0.9+ 970723 360 0.5- 0.6+ 970419 658 0.2- 1.2- 970528 897 1.5+ 0.3+ 1998/ 970419 658 0.9- 1.6- 970530 108 (5.5+ 0.1-) 980213 844 1.9+ 1.6+ 970419 402 0.6- 0.6- 970530 108 0.1+ 0.7+ 980213 844 1.0+ 1.2+ 970419 402 0.0 0.6- 970530 108 1.2+ 2.0+ 980220 860 (2.2+ 0.6-) 970419 402 1.1- 1.2- 970531 360 0.3- 0.3- 980220 860 1.4+ 0.5- 970421 658 0.8- 1.1- 970531 360 0.3- 0.1- 980227 844 1.1+ 1.0+ 970421 658 1.0- 0.4- 970531 402 0.5- 0.4- 980227 844 (2.4+ 0.6-) 970421 658 0.5- 0.7- 970531 402 0.3- 0.4- 980308 860 1.6+ 0.6+ 970422 658 0.5- 0.7- 970531 402 0.3- 0.6- 980308 860 1.0+ 0.8+ 970422 658 0.1- 0.7- 970601 861 0.2- 0.6- 980308 860 0.9+ 0.1- 970422 658 1.5- 1.8- 970601 861 1.1+ 0.4+ 980331 844 0.7- 0.9+ 970429 360 0.6- 0.1+ 970601 861 1.5+ 0.3+ 980331 844 0.6+ 0.8+ 970429 360 0.4- 0.1- 970602 046 0.0 0.6- 980331 844 1.6+ 0.6+ 970429 360 1.2- 0.1+ 970602 046 0.0 0.7- 980420 860 1.5+ 0.3+ 970501 046 0.6- 0.3- 970602 046 0.1- 0.3- 980420 860 1.1+ 0.3+ 970501 046 0.0 0.2- 970604 691 0.1- 0.7+ 980420 860 2.0+ 0.5+ 970501 046 0.4- 0.7- 970604 691 0.1- 0.6+ 980608 860 0.8+ 0.9- 970501 046 0.2- 0.2+ 970604 691 0.1+ 0.4+ 980608 860 0.3+ 0.2+ 970503 691 0.3- 0.0 970606 897 0.6- 0.4- 980619 844 1.7+ 0.5+ 970503 691 0.5- 0.0 970606 897 0.0 0.3- 980619 844 1.5+ 1.7+ 970503 691 0.5- 0.2- 970606 402 0.3+ 0.2+ 980619 844 (1.2+ 2.9+) 970503 104 0.1+ 1.6+ 970606 402 0.1- 0.4- 980625 844 0.4- 0.9- 970503 104 0.1- 1.4+ 970606 402 0.3+ 0.3- 980625 844 0.5+ 0.3+ 970503 104 0.4+ 1.4+ 970607 809 (2.2+ 0.5+) 980625 844 0.3- 1.6- 970504 557 0.2- 0.0 970607 809 1.9+ 1.6+ 980820 422 1.2+ 0.3+ 970504 557 0.6- 0.3+ 970607 809 (2.2+ 1.5+) 980820 422 2.0+ 0.1+ 970504 557 0.2- 0.2- 970607 867 0.5- 0.4- 981001 844 (2.5+ 0.1-) 970504 046 0.5+ 0.3+ 970607 867 0.2- 0.5- 981001 844 2.2+ 1.1- 970504 046 0.5+ 0.6- 970608 809 0.5+ 0.4+ 981001 844 (1.6- 5.0-) 970504 046 0.1+ 0.4- 970608 809 1.5+ 1.1+ 981009 844 1.4- 1.0+ 970505 118 0.2- 0.5- 970608 809 1.2+ 0.8+ 981009 844 1.9+ 1.7- 970505 118 0.8- 0.8- 970608 104 0.1- 0.4- 981009 844 (0.7+ 2.7-) 970506 402 0.4+ 0.1+ 970608 104 0.3- 0.1- 981018 844 1.2+ 1.7- 970506 402 0.2+ 0.0 970608 104 0.0 0.0 981018 844 0.5- 0.7- ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 2008 Sept. 2