Nakano Note (Nakano wa Kangaeru noda) NK 4790 P/2020 A4 (PANSTARRS-Lemmon)
The following improved orbital elements, by S. Nakano, are from 105 observations 2019 Oct. 14 to 2021 Jan. 15. Perturbations by Mercury to Neptune and three minor planets, Ceres, Pallas and Vesta, were taken into account. The mean residual is +/- 0.39 arc second. The comet has passed 1.51 AU from Saturn on 1992 Jan. 7. See an orbit in CBET 5156 (same orbit). Epoch = 2019 Nov. 13.0 TT T = 2019 Nov. 22.74012 +/- 0.00111 (m.e.) TT Peri. = 144.88717 +/- 0.00035 Node = 312.43021 +/- 0.00005 (2000.0) Inc. = 24.98983 +/- 0.00007 q = 2.8425261 +/- 0.0000067 AU e = 0.6536904 +/- 0.0000028 a = 8.2080492 +/- 0.0000699 AU n' = 0.04191256 +/- 0.00000054 P = 23.516 +/- 0.0003004 years (+/- 0.11 day) The predicted orbit for the 2043 return is as follows: T = 2043 May 28.93987 TT Epoch = 2043 May 31.0 TT Peri. = 145.02806 e = 0.6535847 Node = 312.25714 (2000.0) a = 8.1951137 AU Inc. = 25.01586 n'= 0.04201183 q = 2.8389127 AU P = 23.460 years The following residuals in seconds of arc are from the above orbital elements: Date Code Residual(") Date Code Residual(") Date Code Residual(") 2019/ 200123 I41 0.1+ 0.1+ 200212 I41 0.1- 0.7+ 191014 F51 0.1- 0.1+ 200123 I41 0.1+ 0.2+ 200213 I41 0.3- 0.4- 191125 F51 0.3+ 0.0 200123 I41 0.1- 0.4- 200213 I41 0.4- 0.2+ 191127 F51 0.1+ 0.0 200125 I41 0.1- 0.4- 200214 I41 0.2+ 0.2+ 191128 F51 0.0 0.0 200127 I41 0.5- 0.2+ 200214 I41 0.4- 0.1+ 191204 F51 0.1- 0.0 200128 I41 1.0- 0.5+ 200215 I41 0.7+ 0.6- 191209 F52 0.4- 0.3- 200128 I41 0.2+ 0.6+ 200215 I41 0.4+ 0.2+ 191209 F52 0.0 0.2- 200128 I41 0.0 0.0 200215 I41 0.3- 0.1+ 191209 F52 0.1- 0.0 200129 I41 0.2+ 0.4+ 200215 I41 0.5+ 0.4- 191209 F52 0.1+ 0.1- 200129 I41 0.2- 0.8+ 200215 I41 0.2+ 0.3- 191210 F51 0.3+ 0.4+ 200129 I41 0.5+ 0.1+ 200215 I41 0.0 0.5- 191211 F51 0.1- 0.3+ 200130 I41 0.0 0.2- 200216 I41 0.1+ 0.2- 191211 F51 0.0 0.1+ 200131 I41 0.3- 0.8- 200216 I41 0.2+ 0.8+ 191211 F51 0.1+ 0.0 200131 I41 0.2+ 0.5+ 200216 I41 0.2- 0.2+ 191224 F52 0.0 0.1- 200131 I41 0.9- 0.2+ 200216 I41 0.1+ 0.3- 191224 F52 0.1+ 0.1- 200131 I41 0.0 1.0- 200216 I41 0.4+ 0.3- 191224 F52 0.1+ 0.2- 200131 I41 0.5- 0.5+ 200217 I41 0.3- 0.1- 2020/ 200131 I41 0.7- 1.1+ 200217 I41 0.3+ 0.3+ 200101 I41 0.3+ 0.4- 200131 I41 0.7+ 0.3+ 200219 I41 0.4+ 0.1- 200101 I41 0.6- 0.0 200201 I41 0.1- 0.3- 200220 I41 0.9+ 0.6- 200101 I41 0.1- 0.3- 200201 I41 0.2- 0.0 200220 I41 0.2+ 0.1+ 200101 I41 0.3+ 0.2- 200201 I41 0.3- 0.1+ 200221 I41 0.9- 0.8+ 200101 I41 0.4+ 0.0 200202 I41 0.3- 0.1- 200221 I41 0.3- 0.4+ 200101 F51 0.1- 0.1- 200202 I41 0.0 0.5- 200224 I41 0.9+ 0.4- 200101 F51 0.1+ 0.0 200202 I41 0.6- 0.6+ 200224 I41 0.7+ 0.2- 200101 F51 0.1+ 0.1+ 200202 I41 0.1- 0.0 200224 I41 0.1- 0.2- 200101 F51 0.2- 0.1- 200202 I41 0.2- 0.3+ 200225 I41 0.1+ 0.3- 200105 I41 0.4+ 0.1- 200202 I41 0.5- 0.1+ 200225 I41 0.6+ 0.2- 200105 I41 0.0 0.5- 200203 I41 0.2- 0.0 200324 F51 0.2- 0.1- 200105 I41 0.3- 0.1- 200203 I41 0.1+ 0.2- 200324 F51 0.0 0.2- 200114 I41 0.2- 0.4+ 200203 G96 0.0 0.2- 200324 F51 0.1+ 0.5+ 200114 I41 0.0 0.3- 200203 G96 0.0 0.2- 2021/ 200114 I41 0.5+ 0.3+ 200203 G96 0.4+ 0.6- 210115 309 0.8- 0.2+ 200116 I41 1.0- 0.4+ 200203 G96 (0.8+ 2.0-) 210115 309 0.4+ 0.4- 200116 I41 0.0 1.3+ 200212 I41 0.6+ 0.7- 210115 309 0.4+ 0.0 200119 I41 0.1+ 0.4+ 200212 I41 0.2+ 0.6- 200119 I41 0.4- 0.5+ 200212 I41 0.9+ 0.0 ( ) -------- Rejected Obs.
Associate of the CBAT Syuichi Nakano 2022 Aug. 8