メタデータ
| 項目 |
値 |
| Designation |
C/2017 S2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-08-29T08:08:37.178880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:35Z |
| Obs used |
67 |
| NEO |
- |
| M1 |
7.700 |
| K1 |
19.750 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2017-10-10.0000000 |
| e |
0.82311096 |
| q (au) |
3.614508 |
| a (au) |
20.433760 |
| i (deg) |
12.683350 |
| Ω (om, deg) |
62.427792 |
| ω (w, deg) |
305.972876 |
| M (ma, deg) |
0.444537 |
等級
散乱 + 全体線形
$$
M_a = (13.505 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
13.505 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.753 |
| k |
0.800 |
| 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) |
| 2026-06-01 00:00 |
10:06:14.21 |
+24:59:00.6 |
HIP 49430 |
14.45 |
| 2026-06-01 12:00 |
10:06:16.50 |
+24:58:27.4 |
HIP 49430 |
14.49 |
| 2026-06-02 00:00 |
10:06:18.84 |
+24:57:54.1 |
HIP 49430 |
14.58 |
| 2026-06-02 12:00 |
10:06:21.23 |
+24:57:20.6 |
HIP 49430 |
14.71 |
| 2026-06-03 00:00 |
10:06:23.68 |
+24:56:46.9 |
HIP 49430 |
14.89 |
| 2026-06-03 12:00 |
10:06:26.18 |
+24:56:12.9 |
HIP 49430 |
15.12 |
| 2026-06-04 00:00 |
10:06:28.73 |
+24:55:38.8 |
HIP 49430 |
15.40 |
| 2026-06-04 12:00 |
10:06:31.33 |
+24:55:04.5 |
HIP 49430 |
15.72 |
| 2026-06-05 00:00 |
10:06:33.98 |
+24:54:30.0 |
HIP 49430 |
16.09 |
| 2026-06-05 12:00 |
10:06:36.69 |
+24:53:55.3 |
HIP 49430 |
16.50 |
| 2026-06-06 00:00 |
10:06:39.44 |
+24:53:20.4 |
HIP 49430 |
16.96 |
| 2026-06-06 12:00 |
10:06:42.25 |
+24:52:45.4 |
HIP 49430 |
17.46 |
| 2026-06-07 00:00 |
10:06:45.11 |
+24:52:10.1 |
HIP 49430 |
17.99 |
| 2026-06-07 12:00 |
10:06:48.02 |
+24:51:34.7 |
HIP 49430 |
18.57 |
| 2026-06-08 00:00 |
10:06:50.98 |
+24:50:59.1 |
HIP 49430 |
19.17 |
| 2026-06-08 12:00 |
10:06:53.98 |
+24:50:23.3 |
HIP 49430 |
19.81 |
| 2026-06-09 00:00 |
10:06:57.04 |
+24:49:47.3 |
HIP 49430 |
20.49 |
| 2026-06-09 12:00 |
10:07:00.15 |
+24:49:11.1 |
HIP 49430 |
21.19 |
| 2026-06-10 00:00 |
10:07:03.31 |
+24:48:34.8 |
HIP 49430 |
21.92 |
| 2026-06-10 12:00 |
10:07:06.52 |
+24:47:58.3 |
HIP 49430 |
22.68 |
| 2026-06-11 00:00 |
10:07:09.78 |
+24:47:21.7 |
HIP 49430 |
23.46 |
| 2026-06-11 12:00 |
10:07:13.08 |
+24:46:44.9 |
HIP 49430 |
24.27 |
| 2026-06-12 00:00 |
10:07:16.44 |
+24:46:07.9 |
HIP 49430 |
25.10 |
| 2026-06-12 12:00 |
10:07:19.84 |
+24:45:30.7 |
HIP 49691 |
25.64 |
| 2026-06-13 00:00 |
10:07:23.29 |
+24:44:53.4 |
HIP 49691 |
24.65 |
| 2026-06-13 12:00 |
10:07:26.79 |
+24:44:15.9 |
HIP 49691 |
23.65 |
| 2026-06-14 00:00 |
10:07:30.34 |
+24:43:38.3 |
HIP 49691 |
22.64 |
| 2026-06-14 12:00 |
10:07:33.94 |
+24:43:00.5 |
HIP 49691 |
21.63 |
| 2026-06-15 00:00 |
10:07:37.58 |
+24:42:22.6 |
HIP 49691 |
20.61 |
| 2026-06-15 12:00 |
10:07:41.27 |
+24:41:44.5 |
HIP 49691 |
19.58 |
| 2026-06-16 00:00 |
10:07:45.01 |
+24:41:06.3 |
HIP 49691 |
18.54 |
| 2026-06-16 12:00 |
10:07:48.79 |
+24:40:27.9 |
HIP 49691 |
17.50 |
| 2026-06-17 00:00 |
10:07:52.62 |
+24:39:49.4 |
HIP 49691 |
16.45 |
| 2026-06-17 12:00 |
10:07:56.50 |
+24:39:10.7 |
HIP 49691 |
15.40 |
| 2026-06-18 00:00 |
10:08:00.42 |
+24:38:32.0 |
HIP 49691 |
14.35 |
| 2026-06-18 12:00 |
10:08:04.38 |
+24:37:53.0 |
HIP 49691 |
13.29 |
| 2026-06-19 00:00 |
10:08:08.40 |
+24:37:14.0 |
HIP 49691 |
12.24 |
| 2026-06-19 12:00 |
10:08:12.45 |
+24:36:34.8 |
HIP 49691 |
11.20 |
| 2026-06-20 00:00 |
10:08:16.55 |
+24:35:55.5 |
HIP 49691 |
10.17 |
| 2026-06-20 12:00 |
10:08:20.70 |
+24:35:16.1 |
HIP 49691 |
9.16 |
| 2026-06-21 00:00 |
10:08:24.88 |
+24:34:36.5 |
HIP 49691 |
8.18 |
| 2026-06-21 12:00 |
10:08:29.12 |
+24:33:56.8 |
HIP 49691 |
7.24 |
| 2026-06-22 00:00 |
10:08:33.39 |
+24:33:17.0 |
HIP 49691 |
6.39 |