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) |
| 2026-09-20 00:00 |
07:52:53.36 |
-43:02:57.3 |
HIP 38370 |
16.48 |
| 2026-09-20 12:00 |
07:52:54.97 |
-43:03:31.1 |
HIP 38370 |
17.05 |
| 2026-09-21 00:00 |
07:52:56.56 |
-43:04:05.1 |
HIP 38370 |
17.63 |
| 2026-09-21 12:00 |
07:52:58.12 |
-43:04:39.2 |
HIP 38355 |
17.88 |
| 2026-09-22 00:00 |
07:52:59.65 |
-43:05:13.4 |
HIP 38355 |
18.14 |
| 2026-09-22 12:00 |
07:53:01.16 |
-43:05:47.7 |
HIP 38355 |
18.40 |
| 2026-09-23 00:00 |
07:53:02.64 |
-43:06:22.1 |
HIP 38355 |
18.68 |
| 2026-09-23 12:00 |
07:53:04.09 |
-43:06:56.7 |
HIP 38355 |
18.98 |
| 2026-09-24 00:00 |
07:53:05.51 |
-43:07:31.3 |
HIP 38355 |
19.28 |
| 2026-09-24 12:00 |
07:53:06.91 |
-43:08:06.1 |
HIP 38355 |
19.59 |
| 2026-09-25 00:00 |
07:53:08.28 |
-43:08:41.0 |
HIP 38355 |
19.92 |
| 2026-09-25 12:00 |
07:53:09.62 |
-43:09:15.9 |
HIP 38355 |
20.25 |
| 2026-09-26 00:00 |
07:53:10.93 |
-43:09:51.0 |
HIP 38355 |
20.60 |
| 2026-09-26 12:00 |
07:53:12.21 |
-43:10:26.2 |
HIP 38355 |
20.95 |
| 2026-09-27 00:00 |
07:53:13.47 |
-43:11:01.5 |
HIP 38355 |
21.31 |
| 2026-09-27 12:00 |
07:53:14.70 |
-43:11:36.9 |
HIP 38355 |
21.68 |
| 2026-09-28 00:00 |
07:53:15.90 |
-43:12:12.3 |
HIP 38355 |
22.05 |
| 2026-09-28 12:00 |
07:53:17.07 |
-43:12:47.9 |
HIP 38355 |
22.44 |
| 2026-09-29 00:00 |
07:53:18.21 |
-43:13:23.5 |
HIP 38355 |
22.83 |
| 2026-09-29 12:00 |
07:53:19.33 |
-43:13:59.3 |
HIP 38355 |
23.22 |
| 2026-09-30 00:00 |
07:53:20.41 |
-43:14:35.1 |
HIP 38355 |
23.62 |
| 2026-09-30 12:00 |
07:53:21.47 |
-43:15:11.0 |
HIP 38355 |
24.03 |
| 2026-10-01 00:00 |
07:53:22.49 |
-43:15:47.0 |
HIP 38355 |
24.44 |
| 2026-10-01 12:00 |
07:53:23.49 |
-43:16:23.0 |
HIP 38355 |
24.85 |
| 2026-10-02 00:00 |
07:53:24.46 |
-43:16:59.2 |
HIP 38355 |
25.28 |
| 2026-10-02 12:00 |
07:53:25.40 |
-43:17:35.4 |
HIP 38413 |
25.59 |
| 2026-10-03 00:00 |
07:53:26.31 |
-43:18:11.7 |
HIP 38413 |
25.16 |
| 2026-10-03 12:00 |
07:53:27.19 |
-43:18:48.0 |
HIP 38413 |
24.75 |
| 2026-10-04 00:00 |
07:53:28.03 |
-43:19:24.4 |
HIP 38413 |
24.33 |
| 2026-10-04 12:00 |
07:53:28.85 |
-43:20:00.9 |
HIP 38413 |
23.92 |
| 2026-10-05 00:00 |
07:53:29.64 |
-43:20:37.4 |
HIP 38413 |
23.52 |
| 2026-10-05 12:00 |
07:53:30.40 |
-43:21:14.0 |
HIP 38413 |
23.12 |
| 2026-10-06 00:00 |
07:53:31.13 |
-43:21:50.7 |
HIP 38413 |
22.73 |
| 2026-10-06 12:00 |
07:53:31.83 |
-43:22:27.4 |
HIP 38413 |
22.35 |
| 2026-10-07 00:00 |
07:53:32.50 |
-43:23:04.1 |
HIP 38413 |
21.97 |
| 2026-10-07 12:00 |
07:53:33.13 |
-43:23:40.9 |
HIP 38413 |
21.60 |
| 2026-10-08 00:00 |
07:53:33.74 |
-43:24:17.8 |
HIP 38413 |
21.23 |
| 2026-10-08 12:00 |
07:53:34.31 |
-43:24:54.6 |
HIP 38413 |
20.87 |
| 2026-10-09 00:00 |
07:53:34.86 |
-43:25:31.6 |
HIP 38413 |
20.53 |
| 2026-10-09 12:00 |
07:53:35.37 |
-43:26:08.5 |
HIP 38413 |
20.19 |
| 2026-10-10 00:00 |
07:53:35.85 |
-43:26:45.5 |
HIP 38413 |
19.86 |
| 2026-10-10 12:00 |
07:53:36.30 |
-43:27:22.5 |
HIP 38413 |
19.53 |
| 2026-10-11 00:00 |
07:53:36.72 |
-43:27:59.6 |
HIP 38413 |
19.22 |