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) |
| 2026-03-26 00:00 |
19:34:26.87 |
-27:15:52.8 |
HIP 96273 |
6.45 |
| 2026-03-26 12:00 |
19:34:43.91 |
-27:15:39.9 |
HIP 96273 |
6.50 |
| 2026-03-27 00:00 |
19:35:00.79 |
-27:15:27.4 |
HIP 96273 |
8.46 |
| 2026-03-27 12:00 |
19:35:17.53 |
-27:15:15.3 |
HIP 96273 |
11.33 |
| 2026-03-28 00:00 |
19:35:34.11 |
-27:15:03.5 |
HIP 96332 |
13.28 |
| 2026-03-28 12:00 |
19:35:50.53 |
-27:14:52.1 |
HIP 96332 |
15.34 |
| 2026-03-29 00:00 |
19:36:06.80 |
-27:14:41.1 |
HIP 96332 |
17.88 |
| 2026-03-29 12:00 |
19:36:22.90 |
-27:14:30.5 |
HIP 96332 |
20.71 |
| 2026-03-30 00:00 |
19:36:38.86 |
-27:14:20.3 |
HIP 96332 |
23.72 |
| 2026-03-30 12:00 |
19:36:54.65 |
-27:14:10.4 |
HIP 96332 |
26.82 |
| 2026-03-31 00:00 |
19:37:10.28 |
-27:14:01.0 |
HIP 96645 |
24.99 |
| 2026-03-31 12:00 |
19:37:25.75 |
-27:13:52.0 |
HIP 96645 |
21.84 |
| 2026-04-01 00:00 |
19:37:41.06 |
-27:13:43.3 |
HIP 96645 |
18.81 |
| 2026-04-01 12:00 |
19:37:56.20 |
-27:13:35.1 |
HIP 96645 |
15.97 |
| 2026-04-02 00:00 |
19:38:11.18 |
-27:13:27.3 |
HIP 96645 |
13.39 |
| 2026-04-02 12:00 |
19:38:26.00 |
-27:13:19.9 |
HIP 96645 |
11.22 |
| 2026-04-03 00:00 |
19:38:40.65 |
-27:13:12.9 |
HIP 96645 |
9.73 |
| 2026-04-03 12:00 |
19:38:55.13 |
-27:13:06.3 |
HIP 96645 |
9.19 |
| 2026-04-04 00:00 |
19:39:09.44 |
-27:13:00.2 |
HIP 96645 |
9.72 |
| 2026-04-04 12:00 |
19:39:23.58 |
-27:12:54.5 |
HIP 96645 |
11.15 |
| 2026-04-05 00:00 |
19:39:37.56 |
-27:12:49.3 |
HIP 96645 |
13.15 |
| 2026-04-05 12:00 |
19:39:51.36 |
-27:12:44.5 |
HIP 96645 |
15.49 |
| 2026-04-06 00:00 |
19:40:04.99 |
-27:12:40.1 |
HIP 96645 |
18.01 |
| 2026-04-06 12:00 |
19:40:18.44 |
-27:12:36.2 |
HIP 96645 |
20.63 |
| 2026-04-07 00:00 |
19:40:31.72 |
-27:12:32.8 |
HIP 96645 |
23.30 |
| 2026-04-07 12:00 |
19:40:44.83 |
-27:12:29.8 |
HIP 96645 |
25.99 |
| 2026-04-08 00:00 |
19:40:57.75 |
-27:12:27.3 |
HIP 96645 |
28.69 |
| 2026-04-08 12:00 |
19:41:10.50 |
-27:12:25.2 |
HIP 96823 |
29.70 |
| 2026-04-09 00:00 |
19:41:23.07 |
-27:12:23.6 |
HIP 96823 |
30.30 |
| 2026-04-09 12:00 |
19:41:35.45 |
-27:12:22.5 |
HIP 96823 |
31.12 |
| 2026-04-10 00:00 |
19:41:47.66 |
-27:12:21.9 |
HIP 96823 |
32.13 |
| 2026-04-10 12:00 |
19:41:59.68 |
-27:12:21.7 |
HIP 96823 |
33.31 |
| 2026-04-11 00:00 |
19:42:11.52 |
-27:12:22.1 |
HIP 97125 |
33.23 |
| 2026-04-11 12:00 |
19:42:23.17 |
-27:12:22.9 |
HIP 97125 |
30.96 |
| 2026-04-12 00:00 |
19:42:34.64 |
-27:12:24.2 |
HIP 97125 |
28.79 |
| 2026-04-12 12:00 |
19:42:45.92 |
-27:12:26.1 |
HIP 97125 |
26.72 |
| 2026-04-13 00:00 |
19:42:57.01 |
-27:12:28.4 |
HIP 97125 |
24.78 |
| 2026-04-13 12:00 |
19:43:07.91 |
-27:12:31.2 |
HIP 97125 |
22.97 |
| 2026-04-14 00:00 |
19:43:18.61 |
-27:12:34.6 |
HIP 97125 |
21.32 |
| 2026-04-14 12:00 |
19:43:29.13 |
-27:12:38.4 |
HIP 97125 |
19.86 |
| 2026-04-15 00:00 |
19:43:39.45 |
-27:12:42.8 |
HIP 97125 |
18.60 |
| 2026-04-15 12:00 |
19:43:49.58 |
-27:12:47.7 |
HIP 97125 |
17.59 |
| 2026-04-16 00:00 |
19:43:59.51 |
-27:12:53.2 |
HIP 97125 |
16.84 |