メタデータ
| 項目 |
値 |
| 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 |
値 |
| 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
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 |
値 |
| H0 |
12.986 |
| n |
2.066 |
| gf |
1.000 |
| gb |
-0.500 |
| 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) |
| 2026-09-20 00:00 |
20:11:27.82 |
-38:14:57.7 |
HIP 99429 |
7.71 |
| 2026-09-20 12:00 |
20:11:25.77 |
-38:14:48.5 |
HIP 99429 |
7.29 |
| 2026-09-21 00:00 |
20:11:23.75 |
-38:14:39.2 |
HIP 99429 |
6.87 |
| 2026-09-21 12:00 |
20:11:21.75 |
-38:14:29.8 |
HIP 99429 |
6.45 |
| 2026-09-22 00:00 |
20:11:19.79 |
-38:14:20.2 |
HIP 99429 |
6.05 |
| 2026-09-22 12:00 |
20:11:17.86 |
-38:14:10.5 |
HIP 99429 |
5.64 |
| 2026-09-23 00:00 |
20:11:15.96 |
-38:14:00.6 |
HIP 99429 |
5.24 |
| 2026-09-23 12:00 |
20:11:14.09 |
-38:13:50.7 |
HIP 99429 |
4.85 |
| 2026-09-24 00:00 |
20:11:12.24 |
-38:13:40.6 |
HIP 99429 |
4.46 |
| 2026-09-24 12:00 |
20:11:10.43 |
-38:13:30.3 |
HIP 99429 |
4.07 |
| 2026-09-25 00:00 |
20:11:08.65 |
-38:13:20.0 |
HIP 99429 |
3.69 |
| 2026-09-25 12:00 |
20:11:06.89 |
-38:13:09.5 |
HIP 99429 |
3.32 |
| 2026-09-26 00:00 |
20:11:05.17 |
-38:12:58.8 |
HIP 99429 |
2.95 |
| 2026-09-26 12:00 |
20:11:03.48 |
-38:12:48.1 |
HIP 99429 |
2.59 |
| 2026-09-27 00:00 |
20:11:01.82 |
-38:12:37.2 |
HIP 99429 |
2.23 |
| 2026-09-27 12:00 |
20:11:00.19 |
-38:12:26.2 |
HIP 99429 |
1.89 |
| 2026-09-28 00:00 |
20:10:58.59 |
-38:12:15.1 |
HIP 99429 |
1.55 |
| 2026-09-28 12:00 |
20:10:57.02 |
-38:12:03.8 |
HIP 99429 |
1.24 |
| 2026-09-29 00:00 |
20:10:55.48 |
-38:11:52.4 |
HIP 99429 |
0.96 |
| 2026-09-29 12:00 |
20:10:53.97 |
-38:11:40.9 |
HIP 99429 |
0.74 |
| 2026-09-30 00:00 |
20:10:52.50 |
-38:11:29.3 |
HIP 99429 |
0.65 |
| 2026-09-30 12:00 |
20:10:51.05 |
-38:11:17.5 |
HIP 99429 |
0.73 |
| 2026-10-01 00:00 |
20:10:49.64 |
-38:11:05.7 |
HIP 99429 |
0.93 |
| 2026-10-01 12:00 |
20:10:48.26 |
-38:10:53.7 |
HIP 99429 |
1.19 |
| 2026-10-02 00:00 |
20:10:46.90 |
-38:10:41.6 |
HIP 99429 |
1.48 |
| 2026-10-02 12:00 |
20:10:45.59 |
-38:10:29.3 |
HIP 99429 |
1.78 |
| 2026-10-03 00:00 |
20:10:44.30 |
-38:10:17.0 |
HIP 99429 |
2.08 |
| 2026-10-03 12:00 |
20:10:43.04 |
-38:10:04.5 |
HIP 99429 |
2.38 |
| 2026-10-04 00:00 |
20:10:41.82 |
-38:09:52.0 |
HIP 99429 |
2.68 |
| 2026-10-04 12:00 |
20:10:40.63 |
-38:09:39.3 |
HIP 99429 |
2.98 |
| 2026-10-05 00:00 |
20:10:39.47 |
-38:09:26.5 |
HIP 99429 |
3.28 |
| 2026-10-05 12:00 |
20:10:38.35 |
-38:09:13.6 |
HIP 99429 |
3.58 |
| 2026-10-06 00:00 |
20:10:37.25 |
-38:09:00.5 |
HIP 99429 |
3.87 |
| 2026-10-06 12:00 |
20:10:36.19 |
-38:08:47.4 |
HIP 99429 |
4.16 |
| 2026-10-07 00:00 |
20:10:35.16 |
-38:08:34.1 |
HIP 99429 |
4.45 |
| 2026-10-07 12:00 |
20:10:34.17 |
-38:08:20.8 |
HIP 99429 |
4.74 |
| 2026-10-08 00:00 |
20:10:33.20 |
-38:08:07.3 |
HIP 99429 |
5.02 |
| 2026-10-08 12:00 |
20:10:32.27 |
-38:07:53.7 |
HIP 99429 |
5.30 |
| 2026-10-09 00:00 |
20:10:31.38 |
-38:07:40.0 |
HIP 99429 |
5.57 |
| 2026-10-09 12:00 |
20:10:30.51 |
-38:07:26.2 |
HIP 99429 |
5.85 |
| 2026-10-10 00:00 |
20:10:29.68 |
-38:07:12.3 |
HIP 99429 |
6.12 |
| 2026-10-10 12:00 |
20:10:28.88 |
-38:06:58.3 |
HIP 99429 |
6.39 |
| 2026-10-11 00:00 |
20:10:28.12 |
-38:06:44.2 |
HIP 99429 |
6.65 |