Nakano Note (Nakano wa Kangaeru noda) NK 4816 P/Leonard (2020 S6 = 1987 A2 = 2013 Y3)
The following improved orbital elements, by S. Nakano, are from 273 observations 1987 to 2021, 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 +/- 0.62 arc seconds. Identification with X/1987 A2 by M. Meyer who re-measured positions. And observations in 2013/2014 were found by S. Deen. The comet has passed 0.064 AU from Jupiter on 1983 July 1 UT. Before this close approach, orbit was T= 1972 Oct. 22, q= 4.355 AU, e= 0.221, Peri.= 93.0, Node= 250.6, i= 15.7, a= 5.587 AU P= 13.2 years. After this close approach, there is no close approach to Major planets. An orbit from 2013-2021 shows the residual of 1987 observations were +0.08 deg for Right Ascension and -0.02 deg for Declination. See the previous orbits in CBET 4868, NK 4248, NK 4307 and NK 4385. Epoch = 2020 Nov. 7.0 TT T = 2020 Nov. 23.61273 +/- 0.00263 (m.e.) TT Peri. = 176.65407 +/- 0.00122 Node = 242.57109 +/- 0.00006 (2000.0) Inc. = 15.45944 +/- 0.00006 q = 1.8747918 +/- 0.0000027 AU e = 0.4789979 +/- 0.0000007 a = 3.5984340 +/- 0.0000069 AU n' = 0.14438888 +/- 0.00000041 P = 6.826 +/- 0.0000195 years A1 = -0.118 +/- 0.154 A2 = -0.05760 +/- 0.00082 T = 1986 June 19.90883 TT Epoch = 1986 June 19.0 TT Peri. = 176.44411 e = 0.4756270 Node = 242.85094 (2000.0) a = 3.6116209 AU Inc. = 15.41548 n'= 0.14359881 q = 1.8938364 AU P = 6.864 years [ T = 1993 May 7.68658 TT Epoch = 1993 May 13.0 TT Peri. = 176.60068 e = 0.4743935 Node = 242.78598 (2000.0) a = 3.6182241 AU Inc. = 15.39908 n'= 0.14320589 q = 1.9017623 AU P = 6.882 years ] [ T = 2000 Mar. 25.15888 TT Epoch = 2000 Apr. 6.0 TT Peri. = 176.49485 e = 0.4734029 Node = 242.76582 (2000.0) a = 3.6255994 AU Inc. = 15.39852 n'= 0.14276914 q = 1.9092300 AU P = 6.904 years ] [ T = 2007 Feb. 18.72033 TT Epoch = 2007 Mar. 1.0 TT Peri. = 176.42851 e = 0.4717632 Node = 242.76913 (2000.0) a = 3.6310654 AU Inc. = 15.37893 n'= 0.14244689 q = 1.9180625 AU P = 6.919 years ] T = 2014 Jan. 14.57774 TT Epoch = 2014 Jan. 23.0 TT Peri. = 176.46445 e = 0.4736222 Node = 242.73597 (2000.0) a = 3.6212125 AU Inc. = 15.40716 n'= 0.14302865 q = 1.9061258 AU P = 6.891 years The predicted orbit for the 2027 return is as follows: T = 2027 Sept.25.02828 TT Epoch = 2027 Oct. 2.0 TT Peri. = 176.81959 e = 0.4792873 Node = 242.49520 (2000.0) a = 3.5974296 AU Inc. = 15.46572 n'= 0.14444936 q = 1.8732272 AU P = 6.823 years The following residuals in seconds of arc are from the above orbital elements: Date Code Residual(") Date Code Residual(") Date Code Residual(") 1987/ 201018 I52 0.9+ 0.5- 201121 130 1.3+ 0.5- 870105 260 0.4- 0.7- 201019 I52 0.1- 0.2- 201121 130 0.0 0.2- 870105 260 0.3+ 0.5+ 201019 I52 0.2- 0.2- 201121 130 0.7+ 0.0 2013/ 201019 I52 0.1+ 0.6- 201121 W33 0.2- 0.1- 131229 568 0.0 1.4+ 201019 K61 0.9+ 0.1+ 201121 W33 0.0 0.4- 131229 568 0.7- 1.7+ 201019 K61 0.7+ 0.3+ 201121 W33 1.6- 1.2- 2014/ 201019 K61 0.4- 0.2- 201121 Q21 0.5- 0.0 140103 568 0.5+ 0.5+ 201020 858 0.1+ 0.3+ 201121 Q21 1.3- 0.0 140103 568 0.4- 1.8+ 201020 858 0.2- 0.1+ 201122 I81 0.5- 0.0 2020/ 201020 858 0.7- 0.3- 201122 I81 0.6- 0.1- 200828 G96 0.8+ 1.7+ 201020 658 0.3- 0.3- 201122 I81 0.5- 0.2- 200828 G96 0.3- 0.8+ 201020 658 0.4- 0.3- 201123 G96 0.2- 0.3- 200828 G96 0.1- 0.2+ 201020 658 0.5- 0.1- 201123 G96 0.0 0.2- 200918 G96 1.2- 1.2+ 201020 658 0.6- 0.1- 201123 G96 0.1- 0.2- 200918 G96 0.1+ 0.1- 201020 658 0.7- 0.1- 201123 G96 0.2+ 0.8- 200918 G96 0.1- 0.4+ 201020 I52 0.0 0.1+ 201125 703 0.3+ 0.1+ 200918 G96 0.5- 0.0 201020 I52 0.8- 0.8- 201125 703 0.2+ 0.4+ 200922 F52 0.2+ 0.2- 201020 I52 0.5- 0.5- 201125 703 0.1+ 1.4- 200922 F52 0.3- 0.3+ 201020 I52 0.2+ 0.5- 201125 703 0.6- 1.2- 200922 F52 0.5+ 0.1+ 201022 K88 0.5- 0.3- 201202 A77 0.3+ 0.6+ 200929 G96 1.5- 0.3- 201022 K88 0.1+ 0.5- 201202 A77 0.6- 0.1+ 200929 G96 0.4- 0.2+ 201022 K88 1.0- 0.1+ 201202 A77 1.1- 1.8+ 200929 G96 0.4- 0.5- 201023 F52 0.4+ 0.1- 201203 703 0.7+ 0.8- 200929 G96 0.1- 0.1- 201023 Q11 0.2+ 0.2- 201203 703 1.1+ 0.9- 200929 G96 0.3- 0.2- 201023 Q11 0.2+ 0.7- 201203 703 0.3- 0.4+ 200929 G96 0.5- 0.2+ 201023 F52 0.2+ 0.1- 201203 703 1.3+ 1.0+ 200929 G96 1.0- 0.1- 201023 Q11 0.3+ 0.2- 201204 G96 0.8+ 0.2- 200929 G96 0.3- 0.4- 201023 F52 0.2+ 0.1+ 201204 G96 0.8+ 0.0 200929 F52 0.4+ 0.6- 201023 F52 0.2+ 0.0 201204 G96 0.8+ 0.1- 200929 F52 0.1- 0.2+ 201023 941 0.4- 1.1- 201204 G96 0.4+ 0.4- 200929 I52 0.3- 0.1- 201023 941 0.3- 0.6- 201207 Q11 0.2+ 0.1+ 200929 I52 0.0 0.3+ 201023 941 0.8- 0.5- 201207 Q11 0.5+ 0.0 200929 I52 0.5+ 0.6+ 201024 W34 0.6- 0.4- 201207 Q11 0.5+ 0.2+ 200929 I52 0.5- 0.0 201024 W34 0.4- 0.3- 201208 Q11 0.7+ 0.4+ 200929 B49 0.4+ 0.2+ 201024 W34 0.5- 0.1- 201208 Q11 0.2+ 0.3+ 200929 B49 0.6+ 0.1+ 201024 W34 0.6- 0.3- 201208 Q11 0.3+ 0.4+ 200929 B49 1.1- 1.6+ 201024 215 1.1- 0.5- 201209 W88 0.8+ 0.2- 200929 B49 0.5- 0.5+ 201024 215 0.7- 0.2- 201209 W88 0.2+ 0.7- 200930 G96 (2.4- 0.8-) 201024 215 0.5- 0.0 201209 703 0.5- 0.2+ 200930 G96 0.4- 0.1- 201027 G96 0.5- 0.1- 201209 703 0.9+ 0.2- 200930 G96 0.9- 0.5+ 201027 G96 0.1- 0.3+ 201209 703 1.4+ 0.1- 200930 G96 1.6- 0.6- 201027 G96 0.7- 0.5- 201209 703 1.3+ 0.2+ 201007 I52 0.5- 0.8- 201027 G96 0.4- 0.0 201210 F51 0.1- 0.3- 201007 I52 0.0 1.3- 201027 G96 0.0 0.3- 201210 F51 0.0 0.3- 201007 I52 0.3- 0.4+ 201027 G96 0.7- 0.3- 201210 F51 0.1- 0.3- 201007 I52 0.1- 0.8- 201027 G96 0.9- 0.1+ 201210 T08 0.6+ 0.0 201008 L01 0.5+ 0.7+ 201027 G96 0.0 0.0 201210 T08 0.7+ 0.3+ 201008 L01 0.7- 0.3+ 201107 D29 0.3- 0.2- 201210 T08 0.3+ 0.2- 201008 L01 0.2- 0.1- 201107 D29 0.3- 0.3- 201210 T08 (2.2+ 0.2+) 201008 L01 0.7- 0.2- 201107 D29 0.8- 0.3- 201212 T05 1.6+ 0.4- 201008 I52 0.4- 0.3+ 201108 Q11 0.1- 0.2- 201212 T05 (2.1+ 1.1+) 201008 I52 0.0 0.2+ 201108 Q11 0.0 0.1- 201212 T05 0.7+ 0.4- 201008 I52 0.2- 0.3- 201108 Q11 0.4- 0.3- 201212 T05 1.8+ 0.6+ 201008 I52 0.9- 0.3+ 201108 K88 0.6- 0.0 201214 703 1.2+ 0.7- 201009 G96 0.9- 0.0 201108 K88 0.6- 0.7+ 201214 703 1.6+ 0.1+ 201009 G96 0.6- 0.3- 201108 K88 0.4- 0.1- 201214 703 1.0+ 0.2+ 201009 G96 0.7- 0.1- 201109 Q11 0.0 0.3- 201214 703 0.7+ 1.0+ 201009 G96 1.0- 0.2- 201109 Q11 0.1+ 0.1- 201221 703 1.6+ 0.7+ 201009 I52 1.0- 0.1- 201109 Q11 0.0 0.2- 201221 703 1.2+ 1.4+ 201009 I52 0.1- 0.1+ 201109 D29 1.1- 0.1- 201221 703 0.3+ 0.3+ 201009 I52 0.5- 0.0 201109 D29 1.8- 1.1- 201221 703 1.2+ 1.1+ 201009 I52 0.1- 0.6- 201109 D29 1.0- 0.5- 201221 T08 1.0+ 0.7- 201009 N51 0.5- 0.4- 201109 D29 1.7- 1.3- 201221 T08 0.8+ 0.1+ 201009 N51 0.1- 0.0 201109 D29 1.3- 0.4- 201221 T08 0.7+ 0.3+ 201009 N51 0.0 0.1- 201109 D29 (2.6- 1.2-) 201221 T08 1.1+ 0.2+ 201010 Z08 0.4- 0.1+ 201110 703 0.9+ 0.6- 2021/ 201010 Z08 0.1- 0.1- 201110 703 0.7- 0.7- 210106 703 (2.0+ 0.6+) 201010 L07 0.3- 0.1+ 201110 703 0.3- 0.1+ 210106 703 0.9+ 0.6+ 201010 L07 0.5+ 0.1- 201111 X03 1.4- 1.4- 210106 703 0.9+ 0.9+ 201011 C95 (2.2- 0.4-) 201111 X03 0.2- 0.4- 210106 703 (3.0+ 0.3+) 201011 C95 (2.2+ 0.1-) 201111 X03 0.3+ 0.2- 210106 T08 1.7+ 0.5- 201011 H06 0.7- 0.3+ 201111 X03 0.9- 0.0 210106 T08 (2.2+ 0.4+) 201011 H06 0.5- 0.1- 201112 A77 0.4- 0.9- 210106 T08 1.0+ 0.8- 201011 H06 0.3- 0.0 201112 A77 0.7- 1.4- 210106 T08 0.5+ 0.4+ 201011 F52 0.2+ 0.2- 201112 A77 0.5- 0.6- 210108 Q11 0.3+ 0.6+ 201011 F52 0.6+ 0.6- 201112 970 0.3- 0.5- 210108 Q11 0.1+ 0.6+ 201011 F52 0.1- 0.5+ 201112 970 0.6- 0.5+ 210108 Q11 0.2+ 0.7+ 201012 Z08 0.8- 0.0 201113 I81 0.6- 0.9- 210110 G96 0.0 0.4- 201012 Z08 1.0- 0.5- 201113 I81 0.1- 0.6- 210110 G96 0.9+ 0.1- 201013 711 0.3- 0.9+ 201113 I81 0.1+ 0.5- 210110 G96 1.5+ 0.2- 201013 711 0.5- 0.0 201114 K77 1.2- 0.2- 210110 703 (2.4+ 0.1+) 201013 711 0.0 0.0 201114 K77 (1.1- 2.3+) 210110 G96 1.4+ 0.1+ 201013 711 0.1+ 0.0 201115 A77 0.2- 0.0 210110 703 (3.2+ 0.2-) 201014 711 0.6- 0.2+ 201115 A71 0.8- 0.2- 210110 703 (2.2+ 0.3+) 201014 711 0.7- 0.7+ 201115 A71 1.0- 0.3- 210110 703 1.6+ 0.7+ 201014 711 0.1- 0.4+ 201115 A77 0.1- 0.1- 210111 F51 0.1- 0.6- 201014 711 0.1- 0.2+ 201116 703 0.6- 0.0 210111 F51 0.2- 0.6- 201017 587 0.2+ 0.3- 201116 703 0.6- 0.5- 210111 F51 0.0 0.7- 201017 587 0.1- 0.7- 201116 703 0.4- 0.0 210111 F51 0.4+ 0.3- 201017 587 0.1+ 0.6- 201118 970 0.0 0.1- 210118 349 (2.0+ 0.2-) 201017 587 0.1+ 0.4- 201118 970 0.1+ 0.3- 210118 349 1.5+ 0.5+ 201018 204 0.4- 0.1- 201119 703 0.4+ 1.3+ 210206 Q11 0.7+ 0.2- 201018 204 0.6- 0.1+ 201119 703 1.3- 0.5- 210206 Q11 1.0+ 0.3- 201018 A77 0.5- 0.4- 201119 703 0.1- 0.7- 210213 215 0.6- 0.8- 201018 A77 0.2- 0.1- 201119 703 0.7- 1.1- 210213 215 0.3- 0.5- 201018 A77 0.0 0.7- 201120 A77 1.0- 0.7- 210213 215 0.3- 0.8+ 201018 I52 1.2- 0.1- 201120 A77 0.4- 0.5- 201018 I52 0.6+ 0.1- 201120 130 0.6+ 0.7- ( ) -------- Rejected Obs.
Associate of the CBAT Late edition Syuichi Nakano 2022 Sept. 5