OAA computing section circular NK 550 Periodic Comet Peters-Hartley
The following improved orbital elements, by S. Nakano, are from 27 observations 1982 to 1990, including full planetary and five minor planets perturbations. The mean residual is +/- 1.13 arc seconds. Epoch = 1982 Apr. 21.0 ET T = 1982 May 8.56950 +/- 0.00153 (m.e.) ET Peri. = 338.20001 +/- 0.00094 Node = 259.34993 +/- 0.00073 (1950.0) Inc. = 29.85534 +/- 0.00045 q = 1.6226134 +/- 0.0000061 AU e = 0.5983755 +/- 0.0000015 a = 4.0401256 +/- 0.0000006 AU nß = 0.12137012 +/- 0.00000003 P = 8.121 +/- 0.0000018 years T = 1990 June 23.64219 ET Epoch = 1990 July 8.0 ET Peri. = 338.31707 e = 0.5979240 Node = 259.39413 (1950.0) a = 4.0434682 AU Inc. = 29.83479 nß= 0.12121965 q = 1.6257813 AU P = 8.131 years The predicted orbit for the 1998 return is as follows: T = 1998 Aug. 11.73560 ET Epoch = 1998 Aug. 15.0 ET Peri. = 338.42190 e = 0.5980193 Node = 259.29656 (1950.0) a = 4.0399052 AU Inc. = 29.85611 nß= 0.12138005 q = 1.6239641 AU P = 8.120 years The following residuals in seconds of arc are from the above orbital elements: Date/ UT R.A. (1950) Decl. *** O-C *** Code/Obs h m s ¡ , " " " 1982 07 11.46714 16 49 28.44 -07 02 01.2 0.5- 1.0+ 413/SS 1982 07 13.46319 16 50 07.31 -06 17 34.9 ( 0.9- 6.3+) 323/PR 1982 07 14.45139 16 50 29.01 -05 56 53.8 1.2+ 1.2- 323/PR 1982 07 15.17014 16 50 45.58 -05 42 20.8 ( 4.1+ 2.7+) 688/LO 1982 07 15.20556 16 50 46.57 -05 41 37.8 ( 8.1+ 2.9+) 688/LO 1982 07 15.58009 16 50 54.82 -05 33 57.5 2.2+ 1.3+ 474/JN 1982 07 15.61331 16 50 55.38 -05 33 19.7 0.9- 0.6- 474/JN 1982 07 16.19688 16 51 10.36 -05 22 05.2 0.6- 1.2+ 707/ev 1982 07 16.38600 16 51 15.32 -05 18 14.4 0.8- 0.3- 474/JN 1982 07 16.47269 16 51 17.39 -05 16 35.4 0.5+ 1.3- 474/JN 1982 07 17.25451 16 51 37.93 -05 02 00.3 1.0- 0.2- 707/ev 1982 07 19.48403 16 52 42.70 -04 21 58.4 ( 2.9+ 3.1+) 413/SS 1982 07 20.56528 16 53 16.66 -04 03 51.9 ( 2.0+ 4.6+) 323/PR 1982 07 21.57187 16 53 49.97 -03 47 53.9 ( 5.5+ 3.7+) 372/sk 1982 07 22.51777 16 54 22.36 -03 33 12.2 ( 2.9+ 1.1-) 474/JN - continued - P/Peters-Hartley NK 550 - 2 Date/ UT R.A. (1950) Decl. *** O-C *** Code/Obs. h m s ¡ , " " " 1982 07 22.54022 16 54 22.93 -03 32 44.5 ( 0.2+ 6.2+) 474/JN 1982 07 23.06793 16 54 42.09 -03 25 09.4 0.1+ 0.6+ 801/HO 1982 07 23.20035 16 54 46.78 -03 23 12.6 0.4+ 0.1- 707/ev 1982 07 23.40317 16 54 54.34 -03 20 02.5 1.7+ 0.2- 474/JN 1982 07 23.43222 16 54 55.14 -03 19 35.9 1.0- 1.0+ 474/JN 1982 07 24.39216 16 55 30.98 -03 05 54.1 1.9- 0.7+ 474/JN 1982 07 24.42133 16 55 32.07 -03 05 29.2 1.0- 1.1+ 474/JN 1982 07 25.07877 16 55 57.53 -02 56 38.7 0.6+ 0.1+ 801/HO 1982 08 12.29035 17 11 18.84 -00 08 00.5 1.3- 0.7- 675/PL 1982 08 14.24591 17 13 20.02 +00 02 37.4 0.7- 1.5- 675/PL 1982 08 19.04862 17 18 33.38 +00 24 19.4 1.8+ 0.8+ 801/HO 1982 09 11.17715 17 48 00.13 +01 10 21.2 0.9+ 0.6- 675/PL 1990 05 26.44271 11 51 27.91 -38 55 48.2 0.5+ 2.1+ 413/SS 1990 05 29.59606 11 58 22.56 -37 30 58.9 1.1- 0.5- 413/SS 1990 06 11.47326 12 29 27.09 -31 44 24.4 1.6- 0.9- 372/sk 1990 06 15.44177 12 39 39.96 -30 00 24.0 0.6+ 0.9+ 413/SS 1990 06 25.21927 13 05 32.17 -25 58 31.7 ( 7.2+ 3.0+) 675/PL 1990 06 25.25417 13 05 37.30 -25 57 44.9 2.0+ 0.1+ 675/PL 1990 06 26.18802 13 08 07.77 -25 35 59.2 2.6+ 1.8- 675/PL 1990 06 27.54757 13 11 46.40 -25 04 39.7 1.4- 0.3- 372/sk 1990 07 19.50833 14 10 34.75 -18 01 38.9 0.8- 1.3- 372/sk 1990 07 20.37019 14 12 51.59 -17 48 06.0 ( 5.1+ 1.0+) 474/JN 1990 07 20.39166 14 12 55.05 -17 47 45.8 ( 6.7+ 1.2+) 474/JN ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 1991 August 4