Nakano Note (Nakano wa Kangaeru noda) NK 2373 P/Hermann (1999 D1 = 2012 Y2)
The following improved orbital elements, by S. Nakano, are from 121 observations 1999 to 2012. Perturbations by Mercury to Neptune and three minor planets, Ceres, Pallas and Vesta, were taken into account. The mean residual is +/- 0.76 arc second. The object was reported on the NEOCP webpage. Then Gareth V. Williams (MPC) and Maik Meyer (Limburg, Germany) independently suggested that this object is identical to comet P/1999 D1. The residuals for 2012 December observations from the prediction in NK 1780 (= HICQ 2012 = MPC 65940) are -3.03 deg (R. A.) and +3.50 deg (Decl.) with the delta-T correction = +8.90 days. Epoch = 2012 Dec. 19.0 TT T = 2012 Dec. 27.28077 +/- 0.00128 (m.e.) TT Peri. = 173.98425 +/- 0.00083 Node = 348.75561 +/- 0.00009 (2000.0) Inc. = 21.34274 +/- 0.00013 q = 1.6437656 +/- 0.0000065 AU e = 0.7141341 +/- 0.0000011 a = 5.7501288 +/- 0.0000055 AU n' = 0.07148052 +/- 0.00000010 P = 13.788 +/- 0.0000198 years T = 1999 Feb. 18.02245 TT Epoch = 1999 Mar. 3.0 TT Peri. = 173.09527 e = 0.7130300 Node = 349.37675 (2000.0) a = 5.7663674 AU Inc. = 21.52733 n'= 0.07117879 q = 1.6547743 AU P = 13.847 years The predicted orbit for the 2026 return is as follows: T = 2026 Oct. 27.86616 TT Epoch = 2026 Nov. 16.0 TT Peri. = 173.81796 e = 0.7140561 Node = 348.70535 (2000.0) a = 5.8038062 AU Inc. = 21.25049 n'= 0.07049117 q = 1.6595628 AU P = 13.982 years The following residuals in seconds of arc are from the above orbital elements: Date Code Residual(") Date Code Residual(") Date Code Residual(") 1999/ 990224 372 0.4+ 0.9+ 990317 402 1.4+ 0.6- 990215 411 (2.9- 0.9+) 990224 372 0.3- 0.1- 990317 402 0.8+ 0.9- 990220 699 0.4+ 1.5+ 990224 046 0.8+ 0.3+ 990317 402 0.0 1.0+ 990220 699 0.9+ 1.4+ 990224 046 0.5+ 0.1- 990318 428 1.7+ 1.5+ 990220 699 1.0+ 0.2+ 990224 046 0.8+ 0.2+ 990318 046 0.5+ 0.8- 990220 557 0.1+ 0.0 990224 046 0.1+ 1.0+ 990318 046 1.1+ 0.3- 990220 557 0.3- 0.6+ 990225 118 0.3+ 1.8- 990318 046 0.8+ 0.2+ 990220 557 0.6- 0.6- 990225 118 0.9- 1.3- 990318 046 0.7+ 1.0- 990220 557 1.0- 0.2- 990225 118 1.6- 0.6- 990322 704 0.1+ 0.9- 990220 557 1.6- 0.5+ 990225 402 0.5- 1.5- 990322 704 0.2- 0.9+ 990220 557 0.8- 0.3- 990225 402 1.1- 1.7- 990322 704 0.1+ 1.0+ 990221 691 0.7+ 0.2- 990225 402 1.5- 1.6- 990322 704 0.8- 1.8+ 990221 691 0.2+ 0.2- 990225 897 1.5- 1.5+ 990322 704 0.6- 0.5+ 990221 691 0.3+ 0.4- 990225 897 0.2+ 0.1- 990322 897 0.7- 0.5- 990221 897 0.1- 0.5+ 990225 897 (0.2+ 3.4+) 990322 360 0.1- 0.3- 990221 897 0.2- 1.3+ 990225 897 (3.6- 2.7+) 990322 360 0.4- 0.1+ 990221 897 0.6- 1.0+ 990226 046 0.6+ 0.8+ 990322 360 0.6- 0.2- 990221 372 (2.2- 0.1-) 990226 046 0.6+ 0.1+ 990322 897 1.0- 0.3- 990221 897 0.1- 0.3+ 990226 046 0.7+ 1.3+ 990322 897 0.9+ 0.3+ 990221 372 0.7- 0.6+ 990226 120 (3.1- 0.5-) 990322 372 0.2- 0.5+ 990221 372 (0.3+ 3.5+) 990226 120 1.1- 1.9- 990326 860 1.7+ 1.3- 990222 859 0.4- 0.3- 990227 120 (3.0- 2.3-) 990326 860 0.0 1.9+ 990222 859 0.0 0.1- 990227 120 (1.1- 2.2-) 990326 860 (2.9+ 0.3-) 990222 859 0.4+ 0.4+ 990313 113 0.7- 1.0- 990404 402 0.4- 0.1- 990222 711 0.3+ 0.6+ 990313 113 0.5- 1.1- 990404 402 0.7- 1.4+ 990222 711 0.3+ 0.6+ 990313 367 1.0- 0.9- 990404 402 1.4- 1.1+ 990222 711 0.4+ 0.5+ 990313 367 0.4- 0.0 990407 360 0.8- 0.3+ 990222 402 1.3+ 0.5- 990313 104 0.8+ 1.5- 990407 360 0.7- 0.2- 990222 402 0.2- 0.6+ 990313 104 0.7+ 0.4- 990407 360 0.7- 0.6- 990222 355 1.0- 0.0 990313 104 0.9+ 0.1- 990414 693 0.4- 0.4+ 990222 402 0.4+ 0.2+ 990315 108 0.4- 1.0+ 990414 693 0.3- 0.3+ 990222 355 0.2+ 0.0 990315 108 (7.1- 1.8+) 990414 693 0.4- 0.0 990222 355 0.2- 0.4- 990315 108 (1.4+ 2.2+) 990414 360 0.1+ 0.7- 990222 372 0.3+ 0.9+ 990315 118 1.3+ 0.5+ 990414 360 0.3- 0.2+ 990222 372 1.2+ 0.2+ 990315 118 0.4+ 0.4- 990414 360 0.4+ 0.3- 990223 118 1.7+ 0.0 990315 118 1.0+ 0.2- 2012/ 990223 118 1.4+ 0.4+ 990316 402 0.9+ 0.3+ 121222 F51 0.1- 0.1+ 990223 118 0.2+ 0.3+ 990316 402 1.0+ 0.2- 121222 F51 0.0 0.1+ 990223 411 1.5- 0.6+ 990316 402 1.5+ 0.5- 121222 F51 0.1+ 0.1+ 990223 411 0.0 0.3- 990316 372 0.4- 0.8- 121222 F51 0.1+ 0.1+ 990223 411 1.2- 0.8- 990316 897 0.5- 0.1- 121225 807 0.0 0.1- 990224 120 0.9- 0.4- 990316 897 (0.3+ 3.3+) 121225 807 0.2+ 0.1- 990224 120 0.4- 0.5- 990316 360 0.2+ 0.3- 121225 807 0.3- 0.0 990224 120 0.8- 0.9- 990316 360 0.3+ 0.3- 121225 807 0.0 0.1- 990224 120 0.6- 0.5- 990316 360 0.1- 0.1+ 121225 807 0.1+ 0.0 ( ) -------- Rejected Obs.
Associate of Central Bureau for Astronomical Telegrams Syuichi Nakano 2012 Dec. 26