メタデータ
| 項目 |
値 |
| Designation |
C/2017 P2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-12-06T13:31:41.891520Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:35Z |
| Obs used |
50 |
| NEO |
- |
| M1 |
9.300 |
| K1 |
23.750 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2017-09-13.0000000 |
| e |
0.99796653 |
| q (au) |
2.461777 |
| a (au) |
1210.625678 |
| i (deg) |
50.084856 |
| Ω (om, deg) |
165.546359 |
| ω (w, deg) |
132.238805 |
| M (ma, deg) |
359.998021 |
等級
散乱 + 全体線形
$$
M_a = (16.551 + 5.128\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
16.551 |
| n |
5.128 |
| gf |
1.000 |
| gb |
-1.000 |
| 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) |
| 2026-09-20 00:00 |
05:44:08.75 |
-26:45:02.3 |
HIP 27128 |
19.88 |
| 2026-09-20 12:00 |
05:44:09.13 |
-26:46:03.6 |
HIP 27128 |
19.09 |
| 2026-09-21 00:00 |
05:44:09.46 |
-26:47:04.9 |
HIP 27128 |
18.33 |
| 2026-09-21 12:00 |
05:44:09.73 |
-26:48:06.3 |
HIP 27128 |
17.60 |
| 2026-09-22 00:00 |
05:44:09.95 |
-26:49:07.6 |
HIP 27128 |
16.92 |
| 2026-09-22 12:00 |
05:44:10.12 |
-26:50:09.0 |
HIP 27128 |
16.27 |
| 2026-09-23 00:00 |
05:44:10.24 |
-26:51:10.3 |
HIP 27128 |
15.68 |
| 2026-09-23 12:00 |
05:44:10.30 |
-26:52:11.7 |
HIP 27128 |
15.15 |
| 2026-09-24 00:00 |
05:44:10.32 |
-26:53:13.0 |
HIP 27128 |
14.67 |
| 2026-09-24 12:00 |
05:44:10.28 |
-26:54:14.4 |
HIP 27128 |
14.27 |
| 2026-09-25 00:00 |
05:44:10.19 |
-26:55:15.7 |
HIP 27128 |
13.94 |
| 2026-09-25 12:00 |
05:44:10.05 |
-26:56:17.0 |
HIP 27128 |
13.69 |
| 2026-09-26 00:00 |
05:44:09.86 |
-26:57:18.3 |
HIP 27128 |
13.53 |
| 2026-09-26 12:00 |
05:44:09.61 |
-26:58:19.5 |
HIP 27128 |
13.45 |
| 2026-09-27 00:00 |
05:44:09.31 |
-26:59:20.7 |
HIP 27128 |
13.46 |
| 2026-09-27 12:00 |
05:44:08.96 |
-27:00:21.9 |
HIP 27128 |
13.56 |
| 2026-09-28 00:00 |
05:44:08.56 |
-27:01:23.0 |
HIP 27128 |
13.75 |
| 2026-09-28 12:00 |
05:44:08.11 |
-27:02:24.1 |
HIP 27128 |
14.02 |
| 2026-09-29 00:00 |
05:44:07.60 |
-27:03:25.1 |
HIP 27128 |
14.36 |
| 2026-09-29 12:00 |
05:44:07.04 |
-27:04:26.1 |
HIP 27128 |
14.79 |
| 2026-09-30 00:00 |
05:44:06.43 |
-27:05:27.0 |
HIP 27128 |
15.28 |
| 2026-09-30 12:00 |
05:44:05.77 |
-27:06:27.8 |
HIP 27128 |
15.83 |
| 2026-10-01 00:00 |
05:44:05.06 |
-27:07:28.6 |
HIP 27128 |
16.43 |
| 2026-10-01 12:00 |
05:44:04.29 |
-27:08:29.3 |
HIP 27128 |
17.09 |
| 2026-10-02 00:00 |
05:44:03.47 |
-27:09:29.9 |
HIP 27128 |
17.79 |
| 2026-10-02 12:00 |
05:44:02.60 |
-27:10:30.5 |
HIP 27128 |
18.53 |
| 2026-10-03 00:00 |
05:44:01.68 |
-27:11:30.9 |
HIP 27128 |
19.30 |
| 2026-10-03 12:00 |
05:44:00.70 |
-27:12:31.3 |
HIP 27128 |
20.10 |
| 2026-10-04 00:00 |
05:43:59.68 |
-27:13:31.6 |
HIP 27052 |
19.39 |
| 2026-10-04 12:00 |
05:43:58.60 |
-27:14:31.7 |
HIP 27052 |
18.44 |
| 2026-10-05 00:00 |
05:43:57.47 |
-27:15:31.8 |
HIP 27052 |
17.50 |
| 2026-10-05 12:00 |
05:43:56.28 |
-27:16:31.7 |
HIP 27052 |
16.57 |
| 2026-10-06 00:00 |
05:43:55.05 |
-27:17:31.5 |
HIP 27052 |
15.67 |
| 2026-10-06 12:00 |
05:43:53.76 |
-27:18:31.2 |
HIP 27052 |
14.78 |
| 2026-10-07 00:00 |
05:43:52.42 |
-27:19:30.8 |
HIP 27052 |
13.92 |
| 2026-10-07 12:00 |
05:43:51.03 |
-27:20:30.2 |
HIP 27052 |
13.10 |
| 2026-10-08 00:00 |
05:43:49.59 |
-27:21:29.5 |
HIP 27052 |
12.31 |
| 2026-10-08 12:00 |
05:43:48.10 |
-27:22:28.7 |
HIP 27052 |
11.57 |
| 2026-10-09 00:00 |
05:43:46.55 |
-27:23:27.7 |
HIP 27052 |
10.88 |
| 2026-10-09 12:00 |
05:43:44.96 |
-27:24:26.5 |
HIP 27052 |
10.27 |
| 2026-10-10 00:00 |
05:43:43.31 |
-27:25:25.2 |
HIP 27052 |
9.73 |
| 2026-10-10 12:00 |
05:43:41.61 |
-27:26:23.7 |
HIP 27052 |
9.30 |
| 2026-10-11 00:00 |
05:43:39.86 |
-27:27:22.1 |
HIP 27052 |
8.98 |