161P/Hartley-IRAS Orbit by S. Nakano NK 1184 (2005) Last obs. 2005 10 12 (A32)
Equinox 2000.0 T/TT q (AU) e P Peri. Node Inc. Tail(AU) Epoch 2026 Oct. 29.78539 1.2651457 0.8357680 21.4 47.07080 1.47750 95.79143 0.200 2026 June 9.0 pre-T: m1 = 8.5 + 5 log Delta + 15.0 log r post-T: m1 = 8.5 + 5 log Delta + 12.0 log r Date/ 0h TT R.A.(1950) Decl. R.A.(2000) Decl. Delta r Variation Magnitude Mot./PA Elong. P PA/Tail Moon Age h m ¡ , h m ¡ , for T=+1 day m1 , ¡ ¡ ¡ ¡ ¡ ¡ 2025 Dec. 31 01 56.13 -63 53.2 01 57.59 -63 38.6 3.769 3.683 +0.84 - 4.1 19.9 21.3/332 77.5 15.1 63/0.75 88 .84 2026 Jan. 10 01 42.18 -60 43.9 01 43.88 -60 28.9 3.755 3.598 +0.76 - 4.8 19.7 21.1/342 73.3 15.2 75/0.76 111 .56 20 01 33.84 -57 22.7 01 35.71 -57 07.4 3.744 3.513 +0.70 - 5.4 19.6 20.9/350 68.9 15.2 85/0.76 62 .01 30 01 29.78 -53 56.9 01 31.75 -53 41.5 3.735 3.426 +0.65 - 5.9 19.4 20.5/358 64.4 15.0 95/0.76 101 .89 Feb. 9 01 28.89 -50 31.5 01 30.94 -50 16.1 3.723 3.339 +0.61 - 6.3 19.2 20.2/ 4 59.9 14.8 104/0.75 107 .55 19 01 30.38 -47 10.0 01 32.47 -46 54.6 3.706 3.250 +0.58 - 6.7 19.0 19.8/ 10 55.5 14.5 112/0.74 52 .03 Mar. 1 01 33.64 -43 54.6 01 35.78 -43 39.3 3.682 3.161 +0.55 - 7.1 18.8 19.5/ 16 51.4 14.2 121/0.72 117 .93 11 01 38.23 -40 46.8 01 40.39 -40 31.6 3.649 3.071 +0.54 - 7.5 18.6 19.1/ 20 47.8 13.9 131/0.71 98 .54 21 01 43.82 -37 47.2 01 46.00 -37 32.3 3.604 2.981 +0.52 - 7.8 18.4 18.7/ 25 44.8 13.6 141/0.71 51 .05 31 01 50.14 -34 56.5 01 52.34 -34 41.7 3.545 2.889 +0.52 - 8.2 18.2 18.3/ 28 42.5 13.5 151/0.72 131 .95 Apr. 10 01 56.99 -32 14.5 01 59.21 -32 00.0 3.472 2.797 +0.51 - 8.7 17.9 17.9/ 32 41.2 13.7 162/0.74 84 .52 20 02 04.22 -29 41.1 02 06.45 -29 26.9 3.382 2.705 +0.51 - 9.2 17.6 17.5/ 35 41.0 14.1 174/0.78 62 .09 30 02 11.66 -27 16.1 02 13.90 -27 02.1 3.275 2.611 +0.51 - 9.8 17.3 17.1/ 37 41.8 14.9 185/0.85 139 .97 May 10 02 19.18 -24 58.6 02 21.45 -24 44.9 3.151 2.518 +0.51 -10.5 17.0 16.6/ 39 43.6 16.1 196/0.95 68 .49 20 02 26.68 -22 48.0 02 28.97 -22 34.7 3.008 2.424 +0.51 -11.4 16.7 16.1/ 40 46.4 17.6 205/1.08 82 .15 30 02 34.01 -20 43.5 02 36.31 -20 30.5 2.848 2.329 +0.52 -12.4 16.3 15.6/ 40 50.0 19.5 214/1.26 135 .98 June 9 02 41.04 -18 43.5 02 43.35 -18 30.8 2.670 2.235 +0.52 -13.6 15.9 15.0/ 39 54.3 21.6 222/1.48 49 .44 19 02 47.58 -16 46.5 02 49.92 -16 34.1 2.475 2.141 +0.53 -15.2 15.4 14.4/ 36 59.2 24.1 229/1.76 105 .20 29 02 53.41 -14 49.8 02 55.77 -14 37.7 2.264 2.047 +0.54 -17.2 14.9 13.9/ 31 64.7 26.7 235/2.10 121 .99 July 9 02 58.24 -12 49.6 03 00.63 -12 37.7 2.039 1.955 +0.55 -19.8 14.4 13.9/ 21 70.7 29.4 240/2.54 34 .37 19 03 01.61 -10 40.1 03 04.03 -10 28.5 1.801 1.864 +0.55 -23.2 13.8 15.0/ 7 77.4 32.1 246/3.09 129 .26 29 03 02.80 -08 11.6 03 05.25 -07 59.9 1.552 1.775 +0.57 -27.9 13.2 18.8/350 84.7 34.7 250/3.80 100 1.00 Aug. 8 03 00.58 -05 06.2 03 03.07 -04 54.5 1.296 1.689 +0.59 -34.8 12.5 28.3/335 93.1 36.8 254/4.71 38 .29 18 02 52.55 -00 50.4 02 55.10 -00 38.3 1.040 1.606 +0.67 -45.4 11.7 48.9/324 103.0 37.9 257/5.85 156 .30 28 02 33.46 +05 46.7 02 36.09 +05 59.8 0.793 1.529 +0.88 -63.2 10.8 93.0/318 115.5 36.6 256/7.13 67 1.00 Sept. 7 01 50.09 +17 05.5 01 52.81 +17 20.3 0.581 1.459 +1.62 -93.9 9.8 169.5/312 131.5 31.2 245/7.84 77 .21 17 00 09.37 +34 07.6 00 11.97 +34 24.3 0.459 1.397 +4.10 -130.1 9.0 198.9/299 142.2 26.2 194/7.86 130 .33 27 21 24.14 +43 17.1 21 26.04 +43 30.2 0.497 1.345 +7.40 -108.0 8.9 128.0/270 123.9 38.2 127/10.7 54 1.00 Oct. 7 19 31.31 +39 39.8 19 33.02 +39 46.4 0.658 1.304 +6.40 -63.0 9.3 66.5/249 101.8 48.6 93/10.7 118 .15 17 18 40.73 +34 57.9 18 42.52 +35 00.9 0.864 1.278 +4.82 -41.0 9.8 35.7/239 86.4 51.1 76/8.94 63 .34 27 18 16.68 +31 45.5 18 18.56 +31 46.8 1.075 1.266 +3.92 -29.6 10.2 20.3/234 75.3 49.4 65/7.18 106 .99 Nov. 6 18 04.09 +29 43.8 18 06.02 +29 44.2 1.273 1.269 +3.41 -22.3 10.3 11.6/231 66.8 45.9 54/5.81 91 .11 16 17 57.19 +28 31.3 17 59.15 +28 31.1 1.450 1.288 +3.10 -17.1 10.6 6.2/234 60.3 41.8 43/4.77 62 .36 26 17 53.38 +27 55.3 17 55.35 +27 54.9 1.599 1.321 +2.89 -13.2 11.0 2.8/257 55.5 38.0 32/4.01 124 .97 Dec. 6 17 51.33 +27 49.2 17 53.31 +27 48.7 1.718 1.366 +2.75 -10.2 11.3 2.6/326 52.6 35.0 19/3.49 69 .09 16 17 50.24 +28 11.0 17 52.21 +28 10.4 1.806 1.423 +2.65 - 7.7 11.6 5.1/348 51.7 32.9 6/3.15 78 .38 26 17 49.45 +29 00.5 17 51.39 +28 59.8 1.862 1.489 +2.59 - 5.7 11.9 7.9/350 52.7 31.7 353/2.96 119 .94 2027 Jan. 5 17 48.37 +30 18.7 17 50.29 +30 17.9 1.890 1.563 +2.56 - 4.0 12.2 11.2/347 55.6 31.3 340/2.89 60 .07 15 17 46.38 +32 08.2 17 48.24 +32 07.3 1.892 1.642 +2.57 - 2.6 12.5 15.0/342 60.2 31.3 329/2.89 97 .41 25 17 42.66 +34 31.2 17 44.46 +34 30.0 1.871 1.726 +2.61 - 1.2 12.7 19.5/336 66.1 31.4 318/2.92 99 .91 Feb. 4 17 36.20 +37 29.2 17 37.91 +37 27.5 1.835 1.813 +2.70 + 0.2 12.9 24.6/330 73.1 31.3 307/2.97 67 .06 14 17 25.53 +41 01.7 17 27.13 +40 59.3 1.790 1.903 +2.84 + 1.9 13.1 30.3/323 80.9 30.8 297/2.99 108 .46 24 17 08.65 +45 01.8 17 10.12 +44 58.1 1.745 1.995 +3.01 + 4.2 13.3 36.2/316 89.3 29.7 285/2.96 80 .88 Mar. 6 16 42.97 +49 11.9 16 44.31 +49 06.4 1.709 2.088 +3.19 + 7.3 13.5 41.6/306 97.7 28.1 270/2.85 89 .05