メタデータ
| 項目 |
値 |
| Designation |
P/2012 U2 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-12-04T06:27:38.750400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:26Z |
| Obs used |
36 |
| NEO |
- |
| M1 |
12.100 |
| K1 |
10.000 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2012-11-14.0000000 |
| e |
0.50656873 |
| q (au) |
3.627785 |
| a (au) |
7.352159 |
| i (deg) |
10.534475 |
| Ω (om, deg) |
186.863069 |
| ω (w, deg) |
229.534876 |
| M (ma, deg) |
358.997883 |
等級
散乱 + 全体線形
$$
M_a = (9.078 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
9.078 |
| n |
6.000 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.973 |
| 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) |
| 2026-07-29 00:00 |
17:30:49.07 |
-11:38:18.4 |
HIP 85658 |
7.28 |
| 2026-07-29 12:00 |
17:30:42.21 |
-11:38:39.4 |
HIP 85658 |
5.69 |
| 2026-07-30 00:00 |
17:30:35.44 |
-11:39:00.6 |
HIP 85658 |
4.23 |
| 2026-07-30 12:00 |
17:30:28.75 |
-11:39:22.1 |
HIP 85658 |
3.05 |
| 2026-07-31 00:00 |
17:30:22.16 |
-11:39:43.9 |
HIP 85658 |
2.52 |
| 2026-07-31 12:00 |
17:30:15.65 |
-11:40:05.9 |
HIP 85658 |
2.97 |
| 2026-08-01 00:00 |
17:30:09.24 |
-11:40:28.3 |
HIP 85658 |
4.07 |
| 2026-08-01 12:00 |
17:30:02.92 |
-11:40:50.9 |
HIP 85658 |
5.42 |
| 2026-08-02 00:00 |
17:29:56.69 |
-11:41:13.7 |
HIP 85658 |
6.86 |
| 2026-08-02 12:00 |
17:29:50.55 |
-11:41:36.9 |
HIP 85658 |
8.33 |
| 2026-08-03 00:00 |
17:29:44.50 |
-11:42:00.3 |
HIP 85658 |
9.81 |
| 2026-08-03 12:00 |
17:29:38.55 |
-11:42:24.0 |
HIP 85658 |
11.29 |
| 2026-08-04 00:00 |
17:29:32.69 |
-11:42:48.0 |
HIP 85658 |
12.75 |
| 2026-08-04 12:00 |
17:29:26.92 |
-11:43:12.2 |
HIP 85658 |
14.20 |
| 2026-08-05 00:00 |
17:29:21.25 |
-11:43:36.7 |
HIP 85658 |
15.63 |
| 2026-08-05 12:00 |
17:29:15.68 |
-11:44:01.4 |
HIP 85658 |
17.05 |
| 2026-08-06 00:00 |
17:29:10.21 |
-11:44:26.4 |
HIP 85658 |
18.44 |
| 2026-08-06 12:00 |
17:29:04.83 |
-11:44:51.7 |
HIP 85658 |
19.82 |
| 2026-08-07 00:00 |
17:28:59.55 |
-11:45:17.2 |
HIP 85658 |
21.18 |
| 2026-08-07 12:00 |
17:28:54.36 |
-11:45:43.0 |
HIP 85658 |
22.51 |
| 2026-08-08 00:00 |
17:28:49.28 |
-11:46:09.0 |
HIP 85658 |
23.83 |
| 2026-08-08 12:00 |
17:28:44.30 |
-11:46:35.3 |
HIP 85658 |
25.13 |
| 2026-08-09 00:00 |
17:28:39.41 |
-11:47:01.8 |
HIP 85658 |
26.40 |
| 2026-08-09 12:00 |
17:28:34.63 |
-11:47:28.6 |
HIP 85455 |
26.33 |
| 2026-08-10 00:00 |
17:28:29.95 |
-11:47:55.6 |
HIP 85455 |
25.44 |
| 2026-08-10 12:00 |
17:28:25.37 |
-11:48:22.8 |
HIP 85455 |
24.59 |
| 2026-08-11 00:00 |
17:28:20.90 |
-11:48:50.3 |
HIP 85455 |
23.77 |
| 2026-08-11 12:00 |
17:28:16.52 |
-11:49:18.0 |
HIP 85455 |
22.99 |
| 2026-08-12 00:00 |
17:28:12.25 |
-11:49:46.0 |
HIP 85455 |
22.24 |
| 2026-08-12 12:00 |
17:28:08.09 |
-11:50:14.1 |
HIP 85455 |
21.54 |
| 2026-08-13 00:00 |
17:28:04.03 |
-11:50:42.5 |
HIP 85455 |
20.87 |
| 2026-08-13 12:00 |
17:28:00.07 |
-11:51:11.2 |
HIP 85455 |
20.23 |
| 2026-08-14 00:00 |
17:27:56.22 |
-11:51:40.0 |
HIP 85455 |
19.64 |
| 2026-08-14 12:00 |
17:27:52.48 |
-11:52:09.1 |
HIP 85455 |
19.08 |
| 2026-08-15 00:00 |
17:27:48.84 |
-11:52:38.3 |
HIP 85455 |
18.56 |
| 2026-08-15 12:00 |
17:27:45.30 |
-11:53:07.8 |
HIP 85455 |
18.08 |
| 2026-08-16 00:00 |
17:27:41.88 |
-11:53:37.5 |
HIP 85455 |
17.64 |
| 2026-08-16 12:00 |
17:27:38.56 |
-11:54:07.4 |
HIP 85455 |
17.23 |
| 2026-08-17 00:00 |
17:27:35.35 |
-11:54:37.5 |
HIP 85455 |
16.86 |
| 2026-08-17 12:00 |
17:27:32.25 |
-11:55:07.8 |
HIP 85455 |
16.52 |
| 2026-08-18 00:00 |
17:27:29.25 |
-11:55:38.3 |
HIP 85455 |
16.22 |
| 2026-08-18 12:00 |
17:27:26.37 |
-11:56:09.0 |
HIP 85455 |
15.95 |
| 2026-08-19 00:00 |
17:27:23.59 |
-11:56:39.9 |
HIP 85455 |
15.71 |