メタデータ
| 項目 |
値 |
| Designation |
C/2017 A1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-05-17T03:02:11.906880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:28Z |
| Obs used |
196 |
| NEO |
- |
| M1 |
7.900 |
| K1 |
21.750 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2017-02-09.0000000 |
| e |
0.97149920 |
| q (au) |
2.290367 |
| a (au) |
80.361507 |
| i (deg) |
49.793627 |
| Ω (om, deg) |
121.067433 |
| ω (w, deg) |
2.044588 |
| M (ma, deg) |
359.867117 |
等級
散乱 + 全体線形
$$
M_a = (10.659 + 5.781\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.659 |
| n |
5.781 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
1.000 |
| 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 |
18:33:46.07 |
+02:44:33.2 |
HIP 91048 |
16.00 |
| 2026-06-01 12:00 |
18:33:41.48 |
+02:44:40.5 |
HIP 91048 |
16.77 |
| 2026-06-02 00:00 |
18:33:36.87 |
+02:44:47.5 |
HIP 91048 |
17.58 |
| 2026-06-02 12:00 |
18:33:32.24 |
+02:44:54.2 |
HIP 91048 |
18.43 |
| 2026-06-03 00:00 |
18:33:27.59 |
+02:45:00.6 |
HIP 90895 |
18.48 |
| 2026-06-03 12:00 |
18:33:22.91 |
+02:45:06.7 |
HIP 90895 |
17.46 |
| 2026-06-04 00:00 |
18:33:18.22 |
+02:45:12.5 |
HIP 90895 |
16.47 |
| 2026-06-04 12:00 |
18:33:13.50 |
+02:45:18.0 |
HIP 90895 |
15.51 |
| 2026-06-05 00:00 |
18:33:08.76 |
+02:45:23.2 |
HIP 90895 |
14.57 |
| 2026-06-05 12:00 |
18:33:04.01 |
+02:45:28.1 |
HIP 90895 |
13.67 |
| 2026-06-06 00:00 |
18:32:59.23 |
+02:45:32.7 |
HIP 90895 |
12.82 |
| 2026-06-06 12:00 |
18:32:54.44 |
+02:45:37.0 |
HIP 90895 |
12.04 |
| 2026-06-07 00:00 |
18:32:49.62 |
+02:45:41.0 |
HIP 90895 |
11.32 |
| 2026-06-07 12:00 |
18:32:44.79 |
+02:45:44.7 |
HIP 90895 |
10.70 |
| 2026-06-08 00:00 |
18:32:39.94 |
+02:45:48.1 |
HIP 90895 |
10.19 |
| 2026-06-08 12:00 |
18:32:35.08 |
+02:45:51.2 |
HIP 90895 |
9.80 |
| 2026-06-09 00:00 |
18:32:30.19 |
+02:45:54.0 |
HIP 90895 |
9.56 |
| 2026-06-09 12:00 |
18:32:25.30 |
+02:45:56.4 |
HIP 90895 |
9.48 |
| 2026-06-10 00:00 |
18:32:20.38 |
+02:45:58.6 |
HIP 90895 |
9.56 |
| 2026-06-10 12:00 |
18:32:15.45 |
+02:46:00.4 |
HIP 90895 |
9.80 |
| 2026-06-11 00:00 |
18:32:10.50 |
+02:46:01.9 |
HIP 90895 |
10.19 |
| 2026-06-11 12:00 |
18:32:05.54 |
+02:46:03.2 |
HIP 90895 |
10.72 |
| 2026-06-12 00:00 |
18:32:00.56 |
+02:46:04.1 |
HIP 90895 |
11.36 |
| 2026-06-12 12:00 |
18:31:55.57 |
+02:46:04.7 |
HIP 90895 |
12.11 |
| 2026-06-13 00:00 |
18:31:50.57 |
+02:46:05.0 |
HIP 90895 |
12.94 |
| 2026-06-13 12:00 |
18:31:45.55 |
+02:46:04.9 |
HIP 90895 |
13.83 |
| 2026-06-14 00:00 |
18:31:40.52 |
+02:46:04.6 |
HIP 90895 |
14.79 |
| 2026-06-14 12:00 |
18:31:35.48 |
+02:46:03.9 |
HIP 90895 |
15.79 |
| 2026-06-15 00:00 |
18:31:30.43 |
+02:46:02.9 |
HIP 90895 |
16.83 |
| 2026-06-15 12:00 |
18:31:25.36 |
+02:46:01.6 |
HIP 90895 |
17.91 |
| 2026-06-16 00:00 |
18:31:20.29 |
+02:46:00.0 |
HIP 90895 |
19.01 |
| 2026-06-16 12:00 |
18:31:15.20 |
+02:45:58.1 |
HIP 90895 |
20.14 |
| 2026-06-17 00:00 |
18:31:10.11 |
+02:45:55.8 |
HIP 90895 |
21.29 |
| 2026-06-17 12:00 |
18:31:05.00 |
+02:45:53.3 |
HIP 90895 |
22.46 |
| 2026-06-18 00:00 |
18:30:59.89 |
+02:45:50.4 |
HIP 90738 |
23.58 |
| 2026-06-18 12:00 |
18:30:54.77 |
+02:45:47.2 |
HIP 90738 |
23.52 |
| 2026-06-19 00:00 |
18:30:49.64 |
+02:45:43.7 |
HIP 90738 |
23.55 |
| 2026-06-19 12:00 |
18:30:44.50 |
+02:45:39.8 |
HIP 90738 |
23.64 |
| 2026-06-20 00:00 |
18:30:39.36 |
+02:45:35.7 |
HIP 90738 |
23.81 |
| 2026-06-20 12:00 |
18:30:34.21 |
+02:45:31.2 |
HIP 90738 |
24.06 |
| 2026-06-21 00:00 |
18:30:29.05 |
+02:45:26.4 |
HIP 90738 |
24.37 |
| 2026-06-21 12:00 |
18:30:23.89 |
+02:45:21.3 |
HIP 90738 |
24.76 |
| 2026-06-22 00:00 |
18:30:18.72 |
+02:45:15.9 |
HIP 90738 |
25.21 |