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) |
| 2026-03-26 00:00 |
10:09:34.04 |
+25:29:18.6 |
HIP 49719 |
6.83 |
| 2026-03-26 12:00 |
10:09:29.09 |
+25:29:28.4 |
HIP 49719 |
5.71 |
| 2026-03-27 00:00 |
10:09:24.17 |
+25:29:37.9 |
HIP 49719 |
4.61 |
| 2026-03-27 12:00 |
10:09:19.30 |
+25:29:46.9 |
HIP 49719 |
3.52 |
| 2026-03-28 00:00 |
10:09:14.48 |
+25:29:55.6 |
HIP 49719 |
2.47 |
| 2026-03-28 12:00 |
10:09:09.69 |
+25:30:04.0 |
HIP 49719 |
1.49 |
| 2026-03-29 00:00 |
10:09:04.94 |
+25:30:11.9 |
HIP 49719 |
0.86 |
| 2026-03-29 12:00 |
10:09:00.24 |
+25:30:19.4 |
HIP 49719 |
1.26 |
| 2026-03-30 00:00 |
10:08:55.58 |
+25:30:26.6 |
HIP 49719 |
2.16 |
| 2026-03-30 12:00 |
10:08:50.97 |
+25:30:33.4 |
HIP 49719 |
3.16 |
| 2026-03-31 00:00 |
10:08:46.40 |
+25:30:39.8 |
HIP 49719 |
4.17 |
| 2026-03-31 12:00 |
10:08:41.87 |
+25:30:45.8 |
HIP 49719 |
5.18 |
| 2026-04-01 00:00 |
10:08:37.39 |
+25:30:51.5 |
HIP 49719 |
6.18 |
| 2026-04-01 12:00 |
10:08:32.95 |
+25:30:56.7 |
HIP 49719 |
7.18 |
| 2026-04-02 00:00 |
10:08:28.55 |
+25:31:01.6 |
HIP 49719 |
8.17 |
| 2026-04-02 12:00 |
10:08:24.21 |
+25:31:06.1 |
HIP 49719 |
9.15 |
| 2026-04-03 00:00 |
10:08:19.91 |
+25:31:10.2 |
HIP 49719 |
10.12 |
| 2026-04-03 12:00 |
10:08:15.65 |
+25:31:14.0 |
HIP 49719 |
11.08 |
| 2026-04-04 00:00 |
10:08:11.44 |
+25:31:17.3 |
HIP 49719 |
12.03 |
| 2026-04-04 12:00 |
10:08:07.28 |
+25:31:20.3 |
HIP 49719 |
12.97 |
| 2026-04-05 00:00 |
10:08:03.17 |
+25:31:22.9 |
HIP 49719 |
13.90 |
| 2026-04-05 12:00 |
10:07:59.10 |
+25:31:25.1 |
HIP 49719 |
14.82 |
| 2026-04-06 00:00 |
10:07:55.08 |
+25:31:26.9 |
HIP 49719 |
15.73 |
| 2026-04-06 12:00 |
10:07:51.11 |
+25:31:28.4 |
HIP 49719 |
16.62 |
| 2026-04-07 00:00 |
10:07:47.19 |
+25:31:29.5 |
HIP 49719 |
17.51 |
| 2026-04-07 12:00 |
10:07:43.32 |
+25:31:30.2 |
HIP 49719 |
18.38 |
| 2026-04-08 00:00 |
10:07:39.50 |
+25:31:30.5 |
HIP 49719 |
19.24 |
| 2026-04-08 12:00 |
10:07:35.72 |
+25:31:30.5 |
HIP 49719 |
20.10 |
| 2026-04-09 00:00 |
10:07:32.00 |
+25:31:30.0 |
HIP 49719 |
20.93 |
| 2026-04-09 12:00 |
10:07:28.33 |
+25:31:29.2 |
HIP 49719 |
21.76 |
| 2026-04-10 00:00 |
10:07:24.70 |
+25:31:28.0 |
HIP 49719 |
22.58 |
| 2026-04-10 12:00 |
10:07:21.13 |
+25:31:26.5 |
HIP 49719 |
23.39 |
| 2026-04-11 00:00 |
10:07:17.61 |
+25:31:24.5 |
HIP 49719 |
24.18 |
| 2026-04-11 12:00 |
10:07:14.14 |
+25:31:22.2 |
HIP 49719 |
24.96 |
| 2026-04-12 00:00 |
10:07:10.73 |
+25:31:19.5 |
HIP 49719 |
25.73 |
| 2026-04-12 12:00 |
10:07:07.36 |
+25:31:16.5 |
HIP 49719 |
26.49 |
| 2026-04-13 00:00 |
10:07:04.05 |
+25:31:13.1 |
HIP 49719 |
27.24 |
| 2026-04-13 12:00 |
10:07:00.79 |
+25:31:09.2 |
HIP 49719 |
27.97 |
| 2026-04-14 00:00 |
10:06:57.59 |
+25:31:05.1 |
HIP 49719 |
28.70 |
| 2026-04-14 12:00 |
10:06:54.43 |
+25:31:00.5 |
HIP 49719 |
29.41 |
| 2026-04-15 00:00 |
10:06:51.33 |
+25:30:55.6 |
HIP 49719 |
30.11 |
| 2026-04-15 12:00 |
10:06:48.29 |
+25:30:50.3 |
HIP 49719 |
30.79 |
| 2026-04-16 00:00 |
10:06:45.30 |
+25:30:44.6 |
HIP 49719 |
31.47 |