メタデータ
| 項目 |
値 |
| Designation |
C/2004 S1 (Van Ness) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2004-12-08T22:06:25.934400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:43Z |
| Obs used |
122 |
| NEO |
- |
| M1 |
16.000 |
| K1 |
7.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2004-10-08.0000000 |
| e |
0.99999485 |
| q (au) |
0.681767 |
| a (au) |
132276.648552 |
| i (deg) |
114.666841 |
| Ω (om, deg) |
19.219692 |
| ω (w, deg) |
92.816645 |
| M (ma, deg) |
359.999999 |
等級
散乱 + 全体線形
$$
M_a = (17.981 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
17.981 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.680 |
| k |
0.991 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
07:40:14.79 |
-43:50:18.3 |
HIP 37330 |
5.23 |
| 2026-03-26 12:00 |
07:40:13.46 |
-43:49:41.0 |
HIP 37330 |
5.29 |
| 2026-03-27 00:00 |
07:40:12.16 |
-43:49:03.7 |
HIP 37330 |
5.44 |
| 2026-03-27 12:00 |
07:40:10.90 |
-43:48:26.3 |
HIP 37330 |
5.67 |
| 2026-03-28 00:00 |
07:40:09.66 |
-43:47:48.8 |
HIP 37330 |
5.97 |
| 2026-03-28 12:00 |
07:40:08.46 |
-43:47:11.3 |
HIP 37330 |
6.33 |
| 2026-03-29 00:00 |
07:40:07.29 |
-43:46:33.8 |
HIP 37330 |
6.74 |
| 2026-03-29 12:00 |
07:40:06.15 |
-43:45:56.1 |
HIP 37330 |
7.19 |
| 2026-03-30 00:00 |
07:40:05.05 |
-43:45:18.5 |
HIP 37330 |
7.67 |
| 2026-03-30 12:00 |
07:40:03.97 |
-43:44:40.8 |
HIP 37330 |
8.18 |
| 2026-03-31 00:00 |
07:40:02.93 |
-43:44:03.0 |
HIP 37330 |
8.71 |
| 2026-03-31 12:00 |
07:40:01.93 |
-43:43:25.2 |
HIP 37330 |
9.27 |
| 2026-04-01 00:00 |
07:40:00.95 |
-43:42:47.4 |
HIP 37330 |
9.83 |
| 2026-04-01 12:00 |
07:40:00.01 |
-43:42:09.5 |
HIP 37330 |
10.41 |
| 2026-04-02 00:00 |
07:39:59.10 |
-43:41:31.6 |
HIP 37330 |
11.00 |
| 2026-04-02 12:00 |
07:39:58.22 |
-43:40:53.7 |
HIP 37330 |
11.59 |
| 2026-04-03 00:00 |
07:39:57.38 |
-43:40:15.7 |
HIP 37330 |
12.20 |
| 2026-04-03 12:00 |
07:39:56.57 |
-43:39:37.7 |
HIP 37330 |
12.81 |
| 2026-04-04 00:00 |
07:39:55.79 |
-43:38:59.7 |
HIP 37330 |
13.42 |
| 2026-04-04 12:00 |
07:39:55.04 |
-43:38:21.7 |
HIP 37222 |
13.22 |
| 2026-04-05 00:00 |
07:39:54.33 |
-43:37:43.6 |
HIP 37222 |
12.98 |
| 2026-04-05 12:00 |
07:39:53.64 |
-43:37:05.6 |
HIP 37222 |
12.77 |
| 2026-04-06 00:00 |
07:39:53.00 |
-43:36:27.5 |
HIP 37222 |
12.60 |
| 2026-04-06 12:00 |
07:39:52.38 |
-43:35:49.4 |
HIP 37222 |
12.47 |
| 2026-04-07 00:00 |
07:39:51.80 |
-43:35:11.4 |
HIP 37222 |
12.37 |
| 2026-04-07 12:00 |
07:39:51.25 |
-43:34:33.3 |
HIP 37222 |
12.31 |
| 2026-04-08 00:00 |
07:39:50.73 |
-43:33:55.2 |
HIP 37222 |
12.30 |
| 2026-04-08 12:00 |
07:39:50.24 |
-43:33:17.1 |
HIP 37222 |
12.32 |
| 2026-04-09 00:00 |
07:39:49.79 |
-43:32:39.0 |
HIP 37222 |
12.38 |
| 2026-04-09 12:00 |
07:39:49.37 |
-43:32:01.0 |
HIP 37222 |
12.48 |
| 2026-04-10 00:00 |
07:39:48.99 |
-43:31:22.9 |
HIP 37222 |
12.61 |
| 2026-04-10 12:00 |
07:39:48.63 |
-43:30:44.9 |
HIP 37222 |
12.78 |
| 2026-04-11 00:00 |
07:39:48.31 |
-43:30:06.9 |
HIP 37222 |
12.99 |
| 2026-04-11 12:00 |
07:39:48.02 |
-43:29:28.9 |
HIP 37318 |
12.75 |
| 2026-04-12 00:00 |
07:39:47.77 |
-43:28:50.9 |
HIP 37318 |
12.12 |
| 2026-04-12 12:00 |
07:39:47.54 |
-43:28:12.9 |
HIP 37318 |
11.48 |
| 2026-04-13 00:00 |
07:39:47.35 |
-43:27:35.0 |
HIP 37318 |
10.85 |
| 2026-04-13 12:00 |
07:39:47.19 |
-43:26:57.1 |
HIP 37318 |
10.22 |
| 2026-04-14 00:00 |
07:39:47.07 |
-43:26:19.3 |
HIP 37318 |
9.59 |
| 2026-04-14 12:00 |
07:39:46.98 |
-43:25:41.4 |
HIP 37318 |
8.96 |
| 2026-04-15 00:00 |
07:39:46.92 |
-43:25:03.6 |
HIP 37318 |
8.33 |
| 2026-04-15 12:00 |
07:39:46.89 |
-43:24:25.9 |
HIP 37318 |
7.71 |
| 2026-04-16 00:00 |
07:39:46.89 |
-43:23:48.2 |
HIP 37318 |
7.08 |