C/2008 FK75 (Lemmon-Siding Spring)

メタデータ

項目 値
Designation C/2008 FK75 (Lemmon-Siding Spring)
Type C
Perihelion (tp_cal, UTC) 2010-09-29T05:04:17.762880Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:31:18Z
Obs used 3622
NEO -
M1 9.700
K1 5.250
PC -
オスキュレーティング軌道要素
項目 値
Epoch (epoch_cal, TDB) 2010-07-21.0000000
e 1.00270288
q (au) 4.510895
a (au) -1668.924210
i (deg) 61.175512
Ω (om, deg) 218.266231
ω (w, deg) 80.415044
M (ma, deg) -0.001015

等級

C/2008 FK75 (Lemmon-Siding Spring) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (8.961 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目 値
H0 8.961
n 2.000
gf 0.913
gb -1.000
k 0.999
δ90 1.000
パラメータ 記号 範囲 説明
太陽・地球距離が1 AUのときの絶対等級 H0 -5 to 20 彗星の固有の明るさ
測光スロープパラメータ n 2 to 6 太陽距離に対する明るさ変化率
前方散乱非対称係数 gf 0.8 to 1 前方散乱の強さ
後方散乱非対称係数 gb -1 to -0.5 後方散乱の強さ
分配係数 k 0.8 to 1 前方/後方散乱の寄与比
ダスト/ガス明るさ比 δ90 1 to 10 ダスト散乱とガス放射の相対寄与

参考: EPSC-DPS2025-160

天体暦

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-09-20 00:00 04:15:33.75 -10:50:16.0 HIP 19804 19.68
2026-09-20 12:00 04:15:32.58 -10:50:50.5 HIP 19804 20.00
2026-09-21 00:00 04:15:31.37 -10:51:25.0 HIP 19804 20.32
2026-09-21 12:00 04:15:30.14 -10:51:59.4 HIP 19804 20.66
2026-09-22 00:00 04:15:28.87 -10:52:33.8 HIP 19804 21.01
2026-09-22 12:00 04:15:27.58 -10:53:08.2 HIP 19804 21.37
2026-09-23 00:00 04:15:26.26 -10:53:42.6 HIP 19804 21.74
2026-09-23 12:00 04:15:24.90 -10:54:16.9 HIP 19804 22.11
2026-09-24 00:00 04:15:23.52 -10:54:51.2 HIP 19804 22.50
2026-09-24 12:00 04:15:22.10 -10:55:25.4 HIP 19804 22.90
2026-09-25 00:00 04:15:20.66 -10:55:59.6 HIP 19804 23.31
2026-09-25 12:00 04:15:19.19 -10:56:33.8 HIP 19804 23.72
2026-09-26 00:00 04:15:17.69 -10:57:08.0 HIP 19804 24.15
2026-09-26 12:00 04:15:16.16 -10:57:42.1 HIP 19804 24.58
2026-09-27 00:00 04:15:14.60 -10:58:16.1 HIP 19804 25.02
2026-09-27 12:00 04:15:13.01 -10:58:50.1 HIP 19804 25.47
2026-09-28 00:00 04:15:11.39 -10:59:24.1 HIP 19804 25.93
2026-09-28 12:00 04:15:09.74 -10:59:58.0 HIP 19804 26.40
2026-09-29 00:00 04:15:08.07 -11:00:31.8 HIP 19804 26.87
2026-09-29 12:00 04:15:06.36 -11:01:05.6 HIP 19804 27.35
2026-09-30 00:00 04:15:04.63 -11:01:39.3 HIP 19804 27.84
2026-09-30 12:00 04:15:02.87 -11:02:13.0 HIP 19804 28.34
2026-10-01 00:00 04:15:01.08 -11:02:46.6 HIP 19804 28.84
2026-10-01 12:00 04:14:59.26 -11:03:20.1 HIP 19804 29.35
2026-10-02 00:00 04:14:57.42 -11:03:53.6 HIP 19804 29.86
2026-10-02 12:00 04:14:55.54 -11:04:27.0 HIP 19678 29.40
2026-10-03 00:00 04:14:53.64 -11:05:00.3 HIP 19678 28.88
2026-10-03 12:00 04:14:51.72 -11:05:33.5 HIP 19678 28.37
2026-10-04 00:00 04:14:49.76 -11:06:06.7 HIP 19678 27.86
2026-10-04 12:00 04:14:47.78 -11:06:39.8 HIP 19678 27.35
2026-10-05 00:00 04:14:45.76 -11:07:12.8 HIP 19678 26.85
2026-10-05 12:00 04:14:43.73 -11:07:45.7 HIP 19678 26.35
2026-10-06 00:00 04:14:41.66 -11:08:18.5 HIP 19678 25.86
2026-10-06 12:00 04:14:39.57 -11:08:51.3 HIP 19678 25.37
2026-10-07 00:00 04:14:37.45 -11:09:23.9 HIP 19678 24.89
2026-10-07 12:00 04:14:35.30 -11:09:56.4 HIP 19678 24.41
2026-10-08 00:00 04:14:33.13 -11:10:28.9 HIP 19678 23.95
2026-10-08 12:00 04:14:30.93 -11:11:01.2 HIP 19678 23.49
2026-10-09 00:00 04:14:28.71 -11:11:33.5 HIP 19678 23.04
2026-10-09 12:00 04:14:26.46 -11:12:05.6 HIP 19678 22.60
2026-10-10 00:00 04:14:24.19 -11:12:37.6 HIP 19678 22.18
2026-10-10 12:00 04:14:21.88 -11:13:09.5 HIP 19678 21.77
2026-10-11 00:00 04:14:19.56 -11:13:41.3 HIP 19678 21.37