Comet Archive

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C/2008 C1 (Chen-Gao)

メタデータ

項目
Designation C/2008 C1 (Chen-Gao)
Type C
Perihelion (tp_cal, UTC) 2008-04-16T20:25:39.135360Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:31:16Z
Obs used 754
NEO -
M1 13.800
K1 5.250
PC -
オスキュレーティング軌道要素
項目
Epoch (epoch_cal, TDB) 2008-03-06.0000000
e 1.00000066
q (au) 1.262346
a (au) -1909647.271764
i (deg) 61.784520
Ω (om, deg) 307.782377
ω (w, deg) 180.928392
M (ma, deg) -0.000000

等級

C/2008 C1 (Chen-Gao) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (12.986 + 2.066\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目
H0 12.986
n 2.066
gf 0.999
gb -0.998
k 1.000
δ90 10.000
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

残差 (区間線形)

$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$

開始日 (UTC) 終了日 (UTC) a b
2008-01-30 2008-04-16 +12.3117 -3.108

log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)

天体暦

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-02-03 00:00 20:18:48.96 -37:26:19.6 HIP 99949 25.36
2026-02-03 12:00 20:18:52.80 -37:26:10.5 HIP 99949 26.14
2026-02-04 00:00 20:18:56.64 -37:26:01.6 HIP 99949 26.91
2026-02-04 12:00 20:19:00.47 -37:25:52.8 HIP 99949 27.68
2026-02-05 00:00 20:19:04.29 -37:25:44.1 HIP 100335 27.65
2026-02-05 12:00 20:19:08.11 -37:25:35.6 HIP 100335 27.15
2026-02-06 00:00 20:19:11.92 -37:25:27.2 HIP 100335 26.66
2026-02-06 12:00 20:19:15.72 -37:25:19.0 HIP 100335 26.19
2026-02-07 00:00 20:19:19.51 -37:25:10.8 HIP 100335 25.73
2026-02-07 12:00 20:19:23.29 -37:25:02.9 HIP 100335 25.28
2026-02-08 00:00 20:19:27.06 -37:24:55.0 HIP 100335 24.85
2026-02-08 12:00 20:19:30.82 -37:24:47.3 HIP 100335 24.44
2026-02-09 00:00 20:19:34.58 -37:24:39.8 HIP 100335 24.04
2026-02-09 12:00 20:19:38.32 -37:24:32.3 HIP 100335 23.66
2026-02-10 00:00 20:19:42.05 -37:24:25.1 HIP 100335 23.29
2026-02-10 12:00 20:19:45.77 -37:24:17.9 HIP 100335 22.95
2026-02-11 00:00 20:19:49.49 -37:24:10.9 HIP 100335 22.62
2026-02-11 12:00 20:19:53.19 -37:24:04.1 HIP 100335 22.31
2026-02-12 00:00 20:19:56.88 -37:23:57.3 HIP 100335 22.02
2026-02-12 12:00 20:20:00.56 -37:23:50.8 HIP 100335 21.75
2026-02-13 00:00 20:20:04.22 -37:23:44.3 HIP 100335 21.51
2026-02-13 12:00 20:20:07.88 -37:23:38.0 HIP 100335 21.28
2026-02-14 00:00 20:20:11.52 -37:23:31.9 HIP 100335 21.08
2026-02-14 12:00 20:20:15.15 -37:23:25.9 HIP 100335 20.89
2026-02-15 00:00 20:20:18.77 -37:23:20.0 HIP 100335 20.73
2026-02-15 12:00 20:20:22.37 -37:23:14.3 HIP 100335 20.60
2026-02-16 00:00 20:20:25.96 -37:23:08.7 HIP 100335 20.48
2026-02-16 12:00 20:20:29.54 -37:23:03.3 HIP 100335 20.39
2026-02-17 00:00 20:20:33.11 -37:22:58.0 HIP 100335 20.32
2026-02-17 12:00 20:20:36.66 -37:22:52.9 HIP 100335 20.28
2026-02-18 00:00 20:20:40.19 -37:22:47.9 HIP 100335 20.25
2026-02-18 12:00 20:20:43.71 -37:22:43.1 HIP 100335 20.25
2026-02-19 00:00 20:20:47.22 -37:22:38.4 HIP 100335 20.27
2026-02-19 12:00 20:20:50.71 -37:22:33.8 HIP 100335 20.32
2026-02-20 00:00 20:20:54.18 -37:22:29.4 HIP 100335 20.38
2026-02-20 12:00 20:20:57.64 -37:22:25.2 HIP 100335 20.47
2026-02-21 00:00 20:21:01.09 -37:22:21.1 HIP 100335 20.57
2026-02-21 12:00 20:21:04.51 -37:22:17.1 HIP 100335 20.70
2026-02-22 00:00 20:21:07.92 -37:22:13.3 HIP 100502 20.64
2026-02-22 12:00 20:21:11.32 -37:22:09.7 HIP 100502 19.98
2026-02-23 00:00 20:21:14.70 -37:22:06.2 HIP 100502 19.33
2026-02-23 12:00 20:21:18.06 -37:22:02.8 HIP 100502 18.68
2026-02-24 00:00 20:21:21.40 -37:21:59.6 HIP 100502 18.04