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) |
| 2026-03-26 00:00 |
05:16:34.08 |
-26:29:20.0 |
HIP 24521 |
12.57 |
| 2026-03-26 12:00 |
05:16:36.38 |
-26:28:15.8 |
HIP 24521 |
12.88 |
| 2026-03-27 00:00 |
05:16:38.73 |
-26:27:11.8 |
HIP 24521 |
13.31 |
| 2026-03-27 12:00 |
05:16:41.13 |
-26:26:08.0 |
HIP 24521 |
13.83 |
| 2026-03-28 00:00 |
05:16:43.58 |
-26:25:04.4 |
HIP 24521 |
14.45 |
| 2026-03-28 12:00 |
05:16:46.08 |
-26:24:00.9 |
HIP 24521 |
15.15 |
| 2026-03-29 00:00 |
05:16:48.62 |
-26:22:57.6 |
HIP 24521 |
15.91 |
| 2026-03-29 12:00 |
05:16:51.22 |
-26:21:54.5 |
HIP 24521 |
16.74 |
| 2026-03-30 00:00 |
05:16:53.86 |
-26:20:51.5 |
HIP 24521 |
17.62 |
| 2026-03-30 12:00 |
05:16:56.55 |
-26:19:48.8 |
HIP 24521 |
18.54 |
| 2026-03-31 00:00 |
05:16:59.29 |
-26:18:46.2 |
HIP 24521 |
19.51 |
| 2026-03-31 12:00 |
05:17:02.08 |
-26:17:43.9 |
HIP 24521 |
20.51 |
| 2026-04-01 00:00 |
05:17:04.91 |
-26:16:41.7 |
HIP 24521 |
21.53 |
| 2026-04-01 12:00 |
05:17:07.79 |
-26:15:39.8 |
HIP 24521 |
22.59 |
| 2026-04-02 00:00 |
05:17:10.72 |
-26:14:38.0 |
HIP 24521 |
23.67 |
| 2026-04-02 12:00 |
05:17:13.70 |
-26:13:36.5 |
HIP 24521 |
24.77 |
| 2026-04-03 00:00 |
05:17:16.72 |
-26:12:35.2 |
HIP 24521 |
25.88 |
| 2026-04-03 12:00 |
05:17:19.78 |
-26:11:34.0 |
HIP 24521 |
27.02 |
| 2026-04-04 00:00 |
05:17:22.90 |
-26:10:33.2 |
HIP 24677 |
27.97 |
| 2026-04-04 12:00 |
05:17:26.05 |
-26:09:32.5 |
HIP 24677 |
28.89 |
| 2026-04-05 00:00 |
05:17:29.26 |
-26:08:32.1 |
HIP 24677 |
29.83 |
| 2026-04-05 12:00 |
05:17:32.51 |
-26:07:31.8 |
HIP 24677 |
30.79 |
| 2026-04-06 00:00 |
05:17:35.80 |
-26:06:31.9 |
HIP 24860 |
31.28 |
| 2026-04-06 12:00 |
05:17:39.14 |
-26:05:32.1 |
HIP 24860 |
30.24 |
| 2026-04-07 00:00 |
05:17:42.52 |
-26:04:32.6 |
HIP 24860 |
29.20 |
| 2026-04-07 12:00 |
05:17:45.95 |
-26:03:33.4 |
HIP 24860 |
28.18 |
| 2026-04-08 00:00 |
05:17:49.42 |
-26:02:34.4 |
HIP 24860 |
27.17 |
| 2026-04-08 12:00 |
05:17:52.93 |
-26:01:35.7 |
HIP 24860 |
26.17 |
| 2026-04-09 00:00 |
05:17:56.49 |
-26:00:37.2 |
HIP 24860 |
25.18 |
| 2026-04-09 12:00 |
05:18:00.09 |
-25:59:38.9 |
HIP 24860 |
24.21 |
| 2026-04-10 00:00 |
05:18:03.74 |
-25:58:41.0 |
HIP 24860 |
23.26 |
| 2026-04-10 12:00 |
05:18:07.42 |
-25:57:43.3 |
HIP 24860 |
22.33 |
| 2026-04-11 00:00 |
05:18:11.15 |
-25:56:45.8 |
HIP 24860 |
21.43 |
| 2026-04-11 12:00 |
05:18:14.93 |
-25:55:48.7 |
HIP 24860 |
20.55 |
| 2026-04-12 00:00 |
05:18:18.74 |
-25:54:51.8 |
HIP 24860 |
19.71 |
| 2026-04-12 12:00 |
05:18:22.60 |
-25:53:55.2 |
HIP 24860 |
18.91 |
| 2026-04-13 00:00 |
05:18:26.49 |
-25:52:58.9 |
HIP 24860 |
18.15 |
| 2026-04-13 12:00 |
05:18:30.43 |
-25:52:02.8 |
HIP 24860 |
17.45 |
| 2026-04-14 00:00 |
05:18:34.41 |
-25:51:07.1 |
HIP 24860 |
16.80 |
| 2026-04-14 12:00 |
05:18:38.43 |
-25:50:11.7 |
HIP 24860 |
16.22 |
| 2026-04-15 00:00 |
05:18:42.49 |
-25:49:16.5 |
HIP 24860 |
15.72 |
| 2026-04-15 12:00 |
05:18:46.59 |
-25:48:21.7 |
HIP 24860 |
15.29 |
| 2026-04-16 00:00 |
05:18:50.73 |
-25:47:27.1 |
HIP 24860 |
14.96 |