メタデータ
| 項目 |
値 |
| Designation |
C/2020 U5 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2022-04-27T21:04:17.325120Z |
| Orbit solution date (soln_date, UTC) |
2024-04-13T16:42:29Z |
| Obs used |
509 |
| NEO |
- |
| M1 |
12.200 |
| K1 |
4.750 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-10-22T13:23:23.510400Z |
| Discovery magnitude (MPC) |
20.43 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) |
2022-01-04.0000000 |
| e |
0.99935367 |
| q (au) |
3.755932 |
| a (au) |
5811.146481 |
| i (deg) |
97.271094 |
| Ω (om, deg) |
107.337920 |
| ω (w, deg) |
75.415390 |
| M (ma, deg) |
359.999747 |
等級
散乱 + 全体線形
$$
M_a = (12.222 + 3.489\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
12.222 |
| n |
3.489 |
| gf |
0.997 |
| gb |
-0.746 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2020-09-25 |
2021-02-22 |
-0.3995 |
+0.308 |
| 2021-02-22 |
2022-04-21 |
+0.9626 |
-0.954 |
| 2022-04-28 |
2022-12-15 |
+3.8477 |
-1.840 |
| 2022-12-15 |
2024-04-09 |
+7.4296 |
-4.434 |
log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
19:29:35.98 |
-28:59:54.9 |
HIP 95782 |
9.36 |
| 2026-06-01 12:00 |
19:29:26.74 |
-29:01:03.8 |
HIP 95782 |
7.73 |
| 2026-06-02 00:00 |
19:29:17.43 |
-29:02:12.6 |
HIP 95782 |
6.52 |
| 2026-06-02 12:00 |
19:29:08.05 |
-29:03:21.4 |
HIP 95782 |
6.01 |
| 2026-06-03 00:00 |
19:28:58.59 |
-29:04:30.2 |
HIP 95782 |
6.39 |
| 2026-06-03 12:00 |
19:28:49.07 |
-29:05:39.0 |
HIP 95782 |
7.52 |
| 2026-06-04 00:00 |
19:28:39.47 |
-29:06:47.7 |
HIP 95782 |
9.16 |
| 2026-06-04 12:00 |
19:28:29.81 |
-29:07:56.5 |
HIP 95782 |
11.07 |
| 2026-06-05 00:00 |
19:28:20.07 |
-29:09:05.1 |
HIP 95782 |
13.16 |
| 2026-06-05 12:00 |
19:28:10.27 |
-29:10:13.8 |
HIP 95735 |
13.24 |
| 2026-06-06 00:00 |
19:28:00.40 |
-29:11:22.4 |
HIP 95735 |
12.76 |
| 2026-06-06 12:00 |
19:27:50.47 |
-29:12:31.0 |
HIP 95735 |
12.73 |
| 2026-06-07 00:00 |
19:27:40.46 |
-29:13:39.5 |
HIP 95735 |
13.19 |
| 2026-06-07 12:00 |
19:27:30.40 |
-29:14:48.0 |
HIP 95735 |
14.07 |
| 2026-06-08 00:00 |
19:27:20.27 |
-29:15:56.4 |
HIP 95735 |
15.32 |
| 2026-06-08 12:00 |
19:27:10.07 |
-29:17:04.7 |
HIP 95695 |
15.70 |
| 2026-06-09 00:00 |
19:26:59.82 |
-29:18:13.0 |
HIP 95695 |
16.25 |
| 2026-06-09 12:00 |
19:26:49.50 |
-29:19:21.2 |
HIP 95695 |
17.16 |
| 2026-06-10 00:00 |
19:26:39.12 |
-29:20:29.3 |
HIP 95695 |
18.38 |
| 2026-06-10 12:00 |
19:26:28.68 |
-29:21:37.4 |
HIP 95456 |
18.70 |
| 2026-06-11 00:00 |
19:26:18.18 |
-29:22:45.4 |
HIP 95456 |
16.69 |
| 2026-06-11 12:00 |
19:26:07.62 |
-29:23:53.3 |
HIP 95456 |
14.84 |
| 2026-06-12 00:00 |
19:25:57.01 |
-29:25:01.1 |
HIP 95456 |
13.23 |
| 2026-06-12 12:00 |
19:25:46.34 |
-29:26:08.7 |
HIP 95456 |
11.94 |
| 2026-06-13 00:00 |
19:25:35.61 |
-29:27:16.3 |
HIP 95456 |
11.10 |
| 2026-06-13 12:00 |
19:25:24.83 |
-29:28:23.8 |
HIP 95456 |
10.84 |
| 2026-06-14 00:00 |
19:25:13.99 |
-29:29:31.2 |
HIP 95456 |
11.18 |
| 2026-06-14 12:00 |
19:25:03.11 |
-29:30:38.5 |
HIP 95456 |
12.09 |
| 2026-06-15 00:00 |
19:24:52.17 |
-29:31:45.6 |
HIP 95456 |
13.46 |
| 2026-06-15 12:00 |
19:24:41.18 |
-29:32:52.7 |
HIP 95456 |
15.17 |
| 2026-06-16 00:00 |
19:24:30.14 |
-29:33:59.6 |
HIP 95456 |
17.12 |
| 2026-06-16 12:00 |
19:24:19.05 |
-29:35:06.3 |
HIP 95456 |
19.24 |
| 2026-06-17 00:00 |
19:24:07.91 |
-29:36:13.0 |
HIP 95456 |
21.48 |
| 2026-06-17 12:00 |
19:23:56.73 |
-29:37:19.5 |
HIP 95456 |
23.81 |
| 2026-06-18 00:00 |
19:23:45.50 |
-29:38:25.8 |
HIP 95203 |
23.21 |
| 2026-06-18 12:00 |
19:23:34.23 |
-29:39:32.0 |
HIP 95203 |
21.29 |
| 2026-06-19 00:00 |
19:23:22.91 |
-29:40:38.1 |
HIP 95203 |
19.53 |
| 2026-06-19 12:00 |
19:23:11.55 |
-29:41:44.0 |
HIP 95203 |
18.00 |
| 2026-06-20 00:00 |
19:23:00.15 |
-29:42:49.7 |
HIP 95203 |
16.77 |
| 2026-06-20 12:00 |
19:22:48.72 |
-29:43:55.3 |
HIP 95203 |
15.89 |
| 2026-06-21 00:00 |
19:22:37.24 |
-29:45:00.7 |
HIP 95164 |
15.29 |
| 2026-06-21 12:00 |
19:22:25.72 |
-29:46:05.9 |
HIP 95164 |
14.04 |
| 2026-06-22 00:00 |
19:22:14.17 |
-29:47:10.9 |
HIP 95164 |
13.24 |