メタデータ
| 項目 |
値 |
| Designation |
P/2020 U2 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2020-12-25T16:46:43.095360Z |
| Orbit solution date (soln_date, UTC) |
2021-07-01T22:13:00Z |
| Obs used |
301 |
| NEO |
- |
| M1 |
9.900 |
| K1 |
26.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2020-10-20T09:20:45.801600Z |
| Discovery magnitude (MPC) |
21.70 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2021-01-12.0000000 |
| e |
0.51048764 |
| q (au) |
1.848825 |
| a (au) |
3.776871 |
| i (deg) |
6.420975 |
| Ω (om, deg) |
342.901523 |
| ω (w, deg) |
84.644930 |
| M (ma, deg) |
2.323134 |
等級
散乱 + 全体線形
$$
M_a = (12.635 + 5.176\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
12.635 |
| n |
5.176 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| 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) |
| 2026-06-01 00:00 |
19:43:27.28 |
-27:59:20.3 |
HIP 96823 |
39.20 |
| 2026-06-01 12:00 |
19:43:15.97 |
-28:00:11.4 |
HIP 96823 |
37.40 |
| 2026-06-02 00:00 |
19:43:04.42 |
-28:01:02.8 |
HIP 96823 |
35.66 |
| 2026-06-02 12:00 |
19:42:52.65 |
-28:01:54.3 |
HIP 96823 |
34.00 |
| 2026-06-03 00:00 |
19:42:40.64 |
-28:02:46.1 |
HIP 96823 |
32.45 |
| 2026-06-03 12:00 |
19:42:28.40 |
-28:03:38.1 |
HIP 96823 |
31.05 |
| 2026-06-04 00:00 |
19:42:15.93 |
-28:04:30.4 |
HIP 96823 |
29.82 |
| 2026-06-04 12:00 |
19:42:03.24 |
-28:05:22.8 |
HIP 96823 |
28.80 |
| 2026-06-05 00:00 |
19:41:50.31 |
-28:06:15.3 |
HIP 96823 |
28.04 |
| 2026-06-05 12:00 |
19:41:37.16 |
-28:07:08.1 |
HIP 96823 |
27.56 |
| 2026-06-06 00:00 |
19:41:23.79 |
-28:08:01.0 |
HIP 96823 |
27.40 |
| 2026-06-06 12:00 |
19:41:10.19 |
-28:08:54.0 |
HIP 96823 |
27.58 |
| 2026-06-07 00:00 |
19:40:56.36 |
-28:09:47.2 |
HIP 96823 |
28.11 |
| 2026-06-07 12:00 |
19:40:42.32 |
-28:10:40.5 |
HIP 96823 |
28.99 |
| 2026-06-08 00:00 |
19:40:28.05 |
-28:11:33.9 |
HIP 96823 |
30.19 |
| 2026-06-08 12:00 |
19:40:13.57 |
-28:12:27.5 |
HIP 96644 |
29.40 |
| 2026-06-09 00:00 |
19:39:58.86 |
-28:13:21.1 |
HIP 96644 |
26.88 |
| 2026-06-09 12:00 |
19:39:43.94 |
-28:14:14.7 |
HIP 96644 |
24.54 |
| 2026-06-10 00:00 |
19:39:28.81 |
-28:15:08.5 |
HIP 96644 |
22.46 |
| 2026-06-10 12:00 |
19:39:13.46 |
-28:16:02.3 |
HIP 96644 |
20.74 |
| 2026-06-11 00:00 |
19:38:57.89 |
-28:16:56.1 |
HIP 96644 |
19.50 |
| 2026-06-11 12:00 |
19:38:42.12 |
-28:17:49.9 |
HIP 96644 |
18.86 |
| 2026-06-12 00:00 |
19:38:26.14 |
-28:18:43.8 |
HIP 96644 |
18.90 |
| 2026-06-12 12:00 |
19:38:09.95 |
-28:19:37.6 |
HIP 96644 |
19.64 |
| 2026-06-13 00:00 |
19:37:53.56 |
-28:20:31.5 |
HIP 96644 |
21.04 |
| 2026-06-13 12:00 |
19:37:36.96 |
-28:21:25.3 |
HIP 96644 |
22.99 |
| 2026-06-14 00:00 |
19:37:20.16 |
-28:22:19.0 |
HIP 96438 |
21.76 |
| 2026-06-14 12:00 |
19:37:03.17 |
-28:23:12.8 |
HIP 96438 |
19.13 |
| 2026-06-15 00:00 |
19:36:45.97 |
-28:24:06.4 |
HIP 96438 |
16.97 |
| 2026-06-15 12:00 |
19:36:28.59 |
-28:25:00.0 |
HIP 96438 |
15.49 |
| 2026-06-16 00:00 |
19:36:11.01 |
-28:25:53.4 |
HIP 96408 |
14.32 |
| 2026-06-16 12:00 |
19:35:53.24 |
-28:26:46.7 |
HIP 96408 |
13.50 |
| 2026-06-17 00:00 |
19:35:35.29 |
-28:27:39.9 |
HIP 96408 |
13.86 |
| 2026-06-17 12:00 |
19:35:17.15 |
-28:28:33.0 |
HIP 96408 |
15.35 |
| 2026-06-18 00:00 |
19:34:58.83 |
-28:29:25.9 |
HIP 96408 |
17.70 |
| 2026-06-18 12:00 |
19:34:40.33 |
-28:30:18.6 |
HIP 96293 |
19.08 |
| 2026-06-19 00:00 |
19:34:21.65 |
-28:31:11.1 |
HIP 96293 |
18.86 |
| 2026-06-19 12:00 |
19:34:02.80 |
-28:32:03.4 |
HIP 96293 |
19.59 |
| 2026-06-20 00:00 |
19:33:43.78 |
-28:32:55.6 |
HIP 96293 |
21.17 |
| 2026-06-20 12:00 |
19:33:24.60 |
-28:33:47.4 |
HIP 96094 |
19.17 |
| 2026-06-21 00:00 |
19:33:05.24 |
-28:34:39.1 |
HIP 96094 |
16.54 |
| 2026-06-21 12:00 |
19:32:45.73 |
-28:35:30.5 |
HIP 96094 |
14.74 |
| 2026-06-22 00:00 |
19:32:26.05 |
-28:36:21.6 |
HIP 96094 |
14.09 |