December 21, 2015A12:55:16 UT Orbital elements: C/2015 X8 (NEOWISE) Epoch 2015 Oct. 25.0 TT = JDT 2457320.5 T 2015 Oct. 25.51488 TT Sato q 1.2126180 (2000.0) P Q z +0.0131020 Peri. 22.88712 -0.97257725 +0.21754942 +/-0.0265616 Node 191.29913 +0.08702377 +0.66835867 e 0.9841123 Incl. 155.17732 +0.21568578 +0.71131493 From 33 observations 2015 Dec. 14-21, mean residual 0".73. Epoch 2016 Jan. 13.0 TT = JDT 2457400.5 T 2015 Oct. 25.51272 TT Sato q 1.2126138 (2000.0) P Q z +0.0131418 Peri. 22.88613 -0.97258313 +0.21752145 +/-0.0265616 Node 191.29982 +0.08700232 +0.66836483 e 0.9840641 Incl. 155.17750 +0.21566791 +0.71131770 Residuals in seconds of arc 151214 C51 (5.7+ 2.1-) 151218 695 1.0- 1.1- 151219 349 1.0+ 0.5- 151214 C51 0.1+ 0.1- 151218 695 0.7- 0.3- 151219 349 0.3+ 0.6- 151214 C51 0.3+ 0.4- 151218 U69 0.3+ 0.6+ 151219 349 0.7+ 1.4- 151214 C51 0.0 0.4- 151218 695 0.5- 0.4- 151219 D81 0.5+ 0.6+ 151215 C51 0.4+ 0.1+ 151218 695 0.4- 0.4- 151219 D81 1.0+ 1.3+ 151215 C51 0.1- 0.4+ 151218 695 (2.5- 1.7-) 151220 A71 0.6- 0.7- 151218 I89 0.4- 1.1+ 151219 850 1.6+ 0.3+ 151220 A71 1.3- 0.6- 151218 I89 0.4- 1.2+ 151219 850 0.3+ 0.4- 151221 I89 1.2- 0.5- 151218 I89 0.1+ 1.2+ 151219 850 0.2+ 0.1+ 151221 I89 (0.2- 5.6-) 151218 U69 0.6- 0.8+ 151219 850 0.7+ 0.9+ 151221 I89 (0.5- 2.1-) 151218 U69 0.9- 0.2- 151219 H47 0.1- 1.2- 151221 I89 0.0 1.8+ 151218 U69 0.2- 0.1+ 151219 H47 1.3+ 0.3- 151218 U69 0.2- 0.2+ 151219 H47 0.4- 1.2- December 21, 2015A13:07:12 UT Orbit-1 Orbital elements: C/2015 X8 (NEOWISE) T 2015 Oct. 26.22046 TT Sato q 1.2190699 (2000.0) P Q Peri. 23.53451 -0.97004969 +0.22848854 Node 191.30531 +0.09423694 +0.66681157 e 1.0 Incl. 155.13133 +0.22388164 +0.70933442 From 33 observations 2015 Dec. 14-21, mean residual 0".71. L = 169.7, B = +9.7. Residuals in seconds of arc 151214 C51 (5.4+ 2.0-) 151218 695 0.9- 1.2- 151219 349 1.0+ 0.3- 151214 C51 0.2- 0.1- 151218 695 0.5- 0.4- 151219 349 0.3+ 0.3- 151214 C51 0.0 0.4- 151218 U69 0.5+ 0.4+ 151219 349 0.7+ 1.1- 151214 C51 0.3- 0.4- 151218 695 0.4- 0.6- 151219 D81 0.5+ 0.9+ 151215 C51 0.2+ 0.1+ 151218 695 0.2- 0.5- 151219 D81 1.0+ 1.6+ 151215 C51 0.3- 0.3+ 151218 695 (2.3- 1.9-) 151220 A71 0.6- 0.3- 151218 I89 0.2- 0.9+ 151219 850 1.7+ 0.5+ 151220 A71 1.4- 0.2- 151218 I89 0.2- 1.0+ 151219 850 0.4+ 0.3- 151221 I89 1.6- 0.7+ 151218 I89 0.2+ 1.0+ 151219 850 0.3+ 0.2+ 151221 I89 (0.7- 4.5-) 151218 U69 0.4- 0.6+ 151219 850 0.8+ 1.1+ 151221 I89 1.0- 0.9- 151218 U69 0.7- 0.4- 151219 H47 0.0 1.0- 151221 I89 (0.4- 3.0+) 151218 U69 0.0 0.0 151219 H47 1.4+ 0.1- 151218 U69 0.0 0.1+ 151219 H47 0.4- 1.0- Orbit-2 Orbital elements: C/2015 X8 (NEOWISE) T 2015 Oct. 23.17219 TT Sato q 1.1907186 (2000.0) P Q n 0.01134984 Peri. 20.47091 -0.98055455 +0.17888622 a 19.6099330 Node 191.12915 +0.06192868 +0.67226174 e 0.9392798 Incl. 155.28600 +0.18621926 +0.71837586 P 86.84 From 33 observations 2015 Dec. 14-21, mean residual 0".69. 1/a = +0.0509946, Q = 38.03 AU, L = 172.4, B = +8.4. Residuals in seconds of arc 151214 C51 (5.7+ 1.9-) 151218 695 1.1- 1.3- 151219 349 1.0+ 0.2- 151214 C51 0.1+ 0.0 151218 695 0.7- 0.5- 151219 349 0.3+ 0.3- 151214 C51 0.3+ 0.3- 151218 U69 0.3+ 0.4+ 151219 349 0.7+ 1.1- 151214 C51 0.0 0.3- 151218 695 0.6- 0.6- 151219 D81 0.6+ 0.9+ 151215 C51 0.4+ 0.1+ 151218 695 0.4- 0.6- 151219 D81 1.0+ 1.6+ 151215 C51 0.1- 0.4+ 151218 695 (2.5- 1.9-) 151220 A71 0.5- 0.2- 151218 I89 0.4- 0.8+ 151219 850 1.6+ 0.5+ 151220 A71 1.3- 0.1- 151218 I89 0.4- 0.9+ 151219 850 0.4+ 0.3- 151221 I89 1.0- 0.8+ 151218 I89 0.0 0.9+ 151219 850 0.3+ 0.2+ 151221 I89 (0.1- 4.3-) 151218 U69 0.6- 0.6+ 151219 850 0.8+ 1.1+ 151221 I89 0.3- 0.8- 151218 U69 0.9- 0.4- 151219 H47 0.0 1.0- 151221 I89 (0.2+ 3.2+) 151218 U69 0.2- 0.1- 151219 H47 1.4+ 0.1- 151218 U69 0.2- 0.0 151219 H47 0.4- 1.0- December 19, 2015A07:18:12 UT Orbital elements: C/2015 X8 (NEOWISE) = NM0015a T 2015 Oct. 25.52291 TT Sato q 1.2118958 (2000.0) P Q Peri. 22.20316 -0.97362436 +0.21403128 Node 190.79288 +0.08624781 +0.66595623 e 1.0 Incl. 155.03584 +0.21122716 +0.71462781 From 18 observations 2015 Dec. 14-18, mean residual 0".58. December 18, 2015A05:36:02 UT Orbital elements: NM0015a T 2015 Nov. 4.83035 TT q 1.285448 (2000.0) P Q Peri. 40.4823 -0.9082340 +0.3993550 Node 198.1811 +0.1973001 +0.6721082 e 1.0 Incl. 156.3821 +0.3690308 +0.6235272 From 5 observations 2015 Dec. 14-15, mean residual 1".01. --