メタデータ
| 項目 |
値 |
| Designation |
C/2021 U5 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2022-01-26T14:41:49.295040Z |
| Orbit solution date (soln_date, UTC) |
2022-11-29T21:43:26Z |
| Obs used |
463 |
| NEO |
- |
| M1 |
4.800 |
| K1 |
28.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2021-10-29T11:47:30.652800Z |
| Discovery magnitude (MPC) |
19.16 G |
| Discovery observatory (MPC) |
703 · Catalina Sky Survey |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2022-02-19.0000000 |
| e |
0.98911516 |
| q (au) |
2.363288 |
| a (au) |
217.117490 |
| i (deg) |
39.049400 |
| Ω (om, deg) |
182.755199 |
| ω (w, deg) |
321.471259 |
| M (ma, deg) |
0.007205 |
等級
散乱 + 全体線形
$$
M_a = (12.219 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
12.219 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.744 |
| 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) |
| 2026-05-12 00:00 |
18:27:05.13 |
+17:52:44.2 |
HIP 90420 |
8.91 |
| 2026-05-12 12:00 |
18:26:59.65 |
+17:53:46.3 |
HIP 90420 |
9.75 |
| 2026-05-13 00:00 |
18:26:54.11 |
+17:54:47.8 |
HIP 90420 |
10.78 |
| 2026-05-13 12:00 |
18:26:48.50 |
+17:55:48.8 |
HIP 90420 |
11.94 |
| 2026-05-14 00:00 |
18:26:42.83 |
+17:56:49.1 |
HIP 90420 |
13.21 |
| 2026-05-14 12:00 |
18:26:37.10 |
+17:57:48.8 |
HIP 90420 |
14.56 |
| 2026-05-15 00:00 |
18:26:31.31 |
+17:58:48.0 |
HIP 90420 |
15.97 |
| 2026-05-15 12:00 |
18:26:25.46 |
+17:59:46.4 |
HIP 90420 |
17.43 |
| 2026-05-16 00:00 |
18:26:19.55 |
+18:00:44.3 |
HIP 90420 |
18.92 |
| 2026-05-16 12:00 |
18:26:13.57 |
+18:01:41.5 |
HIP 90312 |
18.00 |
| 2026-05-17 00:00 |
18:26:07.54 |
+18:02:38.1 |
HIP 90312 |
16.52 |
| 2026-05-17 12:00 |
18:26:01.46 |
+18:03:34.0 |
HIP 90312 |
15.10 |
| 2026-05-18 00:00 |
18:25:55.31 |
+18:04:29.3 |
HIP 90312 |
13.76 |
| 2026-05-18 12:00 |
18:25:49.11 |
+18:05:23.9 |
HIP 90312 |
12.52 |
| 2026-05-19 00:00 |
18:25:42.85 |
+18:06:17.9 |
HIP 90312 |
11.41 |
| 2026-05-19 12:00 |
18:25:36.54 |
+18:07:11.2 |
HIP 90312 |
10.50 |
| 2026-05-20 00:00 |
18:25:30.17 |
+18:08:03.8 |
HIP 90312 |
9.82 |
| 2026-05-20 12:00 |
18:25:23.75 |
+18:08:55.7 |
HIP 90312 |
9.43 |
| 2026-05-21 00:00 |
18:25:17.28 |
+18:09:47.0 |
HIP 90312 |
9.39 |
| 2026-05-21 12:00 |
18:25:10.75 |
+18:10:37.5 |
HIP 90312 |
9.68 |
| 2026-05-22 00:00 |
18:25:04.18 |
+18:11:27.4 |
HIP 90312 |
10.29 |
| 2026-05-22 12:00 |
18:24:57.55 |
+18:12:16.6 |
HIP 90312 |
11.16 |
| 2026-05-23 00:00 |
18:24:50.87 |
+18:13:05.1 |
HIP 90312 |
12.25 |
| 2026-05-23 12:00 |
18:24:44.14 |
+18:13:52.9 |
HIP 90312 |
13.50 |
| 2026-05-24 00:00 |
18:24:37.37 |
+18:14:40.0 |
HIP 90312 |
14.87 |
| 2026-05-24 12:00 |
18:24:30.54 |
+18:15:26.3 |
HIP 90270 |
16.33 |
| 2026-05-25 00:00 |
18:24:23.67 |
+18:16:12.0 |
HIP 90270 |
16.67 |
| 2026-05-25 12:00 |
18:24:16.75 |
+18:16:57.0 |
HIP 90270 |
17.22 |
| 2026-05-26 00:00 |
18:24:09.79 |
+18:17:41.2 |
HIP 90270 |
17.94 |
| 2026-05-26 12:00 |
18:24:02.78 |
+18:18:24.7 |
HIP 90270 |
18.83 |
| 2026-05-27 00:00 |
18:23:55.72 |
+18:19:07.4 |
HIP 90270 |
19.86 |
| 2026-05-27 12:00 |
18:23:48.62 |
+18:19:49.5 |
HIP 90270 |
21.01 |
| 2026-05-28 00:00 |
18:23:41.48 |
+18:20:30.8 |
HIP 90270 |
22.27 |
| 2026-05-28 12:00 |
18:23:34.30 |
+18:21:11.4 |
HIP 90270 |
23.61 |
| 2026-05-29 00:00 |
18:23:27.07 |
+18:21:51.2 |
HIP 90270 |
25.03 |
| 2026-05-29 12:00 |
18:23:19.81 |
+18:22:30.3 |
HIP 90270 |
26.51 |
| 2026-05-30 00:00 |
18:23:12.50 |
+18:23:08.6 |
HIP 90270 |
28.05 |
| 2026-05-30 12:00 |
18:23:05.15 |
+18:23:46.2 |
HIP 89972 |
27.03 |
| 2026-05-31 00:00 |
18:22:57.77 |
+18:24:23.0 |
HIP 89972 |
25.85 |
| 2026-05-31 12:00 |
18:22:50.35 |
+18:24:59.1 |
HIP 89972 |
24.73 |
| 2026-06-01 00:00 |
18:22:42.89 |
+18:25:34.4 |
HIP 89972 |
23.70 |
| 2026-06-01 12:00 |
18:22:35.39 |
+18:26:09.0 |
HIP 89972 |
22.75 |
| 2026-06-02 00:00 |
18:22:27.86 |
+18:26:42.7 |
HIP 89972 |
21.91 |