OAA computing section circular NK 564 Comet Helin-Alu (1991r)
The following improved orbital elements, by S. Nakano, are from 34 observations 1991 June 13 to Sept. 13. Perturbations by all nine planets and five minor planets were taken into account. The mean residual is +/- 0.83 arc second. Epoch = 1992 Feb. 28.0 TT T = 1992 Feb. 19.67498 +/- 0.15976 (m.e.) TT Peri. = 30.75359 +/- 0.02470 Node = 253.65393 +/- 0.00015 (2000.0) Inc. = 49.29654 +/- 0.00271 q = 4.8505117 +/- 0.0006315 AU e = 0.9995271 +/- 0.0002467 -1 1/a = 0.0000975 +/- 0.0000509 AU The following residuals in seconds of arc are from the above orbital elements: Date/ UT R.A. (2000) Decl. *** O-C *** Code/Obs. h m s ¡ , " " " 1991 06 13.32257 16 38 54.26 -22 31 48.1 1.8- 0.3- 675/PL 1991 06 13.34722 16 38 53.41 -22 31 36.8 ( 2.6- 0.0 ) 675/PL 1991 06 14.32899 16 38 23.06 -22 24 21.9 ( 2.8+ 1.2-) 675/PL 1991 06 14.35590 16 38 21.98 -22 24 10.5 0.3- 1.8- 675/PL 1991 06 16.24878 16 37 23.67 -22 10 06.9 1.7+ 1.1+ 675/PL 1991 06 16.31753 16 37 21.50 -22 09 38.1 1.5+ 0.6- 675/PL 1991 06 16.34583 16 37 20.55 -22 09 23.6 0.7+ 1.3+ 675/PL 1991 06 16.36701 16 37 19.84 -22 09 12.3 ( 0.0 3.2+) 675/PL 1991 06 17.60451 16 36 42.11 -22 00 07.4 1.9- 0.9- 894/ot 1991 06 17.61771 16 36 41.80 -21 59 59.5 0.5- 1.1+ 894/ot 1991 06 18.26736 16 36 22.42 -21 55 12.1 1.2+ 0.5+ 675/PL 1991 06 18.29896 16 36 21.40 -21 54 59.1 0.6+ 0.5- 675/PL 1991 07 05.50707 16 28 52.49 -19 50 59.0 1.3- 0.4+ 474/JN 1991 07 05.52929 16 28 52.04 -19 50 50.1 0.8- 0.1+ 474/JN 1991 07 08.28368 16 27 55.62 -19 31 59.1 0.2+ 0.2+ 675/PL 1991 07 08.30816 16 27 55.05 -19 31 50.0 0.9- 0.7- 675/PL 1991 07 08.56424 16 27 50.16 -19 30 06.1 0.2+ 1.0- 372/sk 1991 07 08.57674 16 27 50.02 -19 29 58.7 1.8+ 1.3+ 372/sk 1991 07 08.57917 16 27 49.81 -19 29 57.4 0.4- 1.7+ 894/ot 1991 07 09.06775 16 27 40.52 -19 26 40.3 0.4+ 0.6+ 801/HO 1991 07 10.08134 16 27 21.52 -19 19 51.7 0.7+ 0.2- 801/HO 1991 07 10.10049 16 27 21.08 -19 19 43.5 0.4- 0.3+ 801/HO 1991 07 10.24201 16 27 18.47 -19 18 43.2 ( 0.4- 3.5+) 675/PL 1991 07 10.26701 16 27 17.97 -19 18 36.8 0.7- 0.1- 675/PL 1991 07 11.07912 16 27 03.39 -19 13 11.7 0.7- 0.1- 801/HO 1991 07 11.09525 16 27 03.15 -19 13 05.5 0.1+ 0.3- 801/HO 1991 07 11.52016 16 26 55.59 -19 10 13.4 0.5- 0.3- 474/JN 1991 07 11.53926 16 26 55.22 -19 10 06.3 0.9- 0.8- 474/JN 1991 07 13.10329 16 26 29.01 -18 59 50.5 0.4+ 0.6- 801/HO 1991 07 13.12076 16 26 28.75 -18 59 43.1 0.9+ 0.0 801/HO - continued - Comet Helin-Alu (1991r) NK 564 - 2 Date/ UT R.A. (2000) Decl. *** O-C *** Code/Obs. h m s ¡ , " " " 1991 08 06.04181 16 23 35.41 -16 40 32.8 0.5+ 0.6- 801/HO 1991 08 06.06421 16 23 35.43 -16 40 25.7 0.3+ 0.3- 801/HO 1991 08 11.06130 16 23 55.64 -16 16 01.8 0.3+ 0.3- 801/HO 1991 08 13.19583 16 24 10.05 -16 06 11.7 ( 2.4- 6.3-) 675/PL 1991 08 14.17882 16 24 17.93 -16 01 38.9 ( 3.2- 2.1-) 675/PL 1991 08 14.19653 16 24 18.02 -16 01 32.9 ( 3.9- 0.9-) 675/PL 1991 09 07.04882 16 31 09.66 -14 29 47.2 0.0 0.4- 801/HO 1991 09 08.16389 16 31 38.52 -14 26 11.3 1.0- 0.7- 675/PL 1991 09 08.19948 16 31 39.52 -14 26 02.5 0.1+ 1.2+ 675/PL 1991 09 13.01166 16 33 53.78 -14 11 06.2 0.4+ 0.2- 801/HO 1991 09 13.02255 16 33 54.08 -14 11 03.4 0.2+ 0.7+ 801/HO ( ) -------- Rejected Obs.
Director, Computing Section Syuichi Nakano 1991 December 24