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) |
| 2026-03-26 00:00 |
18:30:05.84 |
+15:46:11.0 |
HIP 90669 |
10.59 |
| 2026-03-26 12:00 |
18:30:07.70 |
+15:47:40.5 |
HIP 90669 |
9.21 |
| 2026-03-27 00:00 |
18:30:09.49 |
+15:49:09.9 |
HIP 90669 |
7.88 |
| 2026-03-27 12:00 |
18:30:11.19 |
+15:50:39.3 |
HIP 90669 |
6.64 |
| 2026-03-28 00:00 |
18:30:12.80 |
+15:52:08.8 |
HIP 90669 |
5.54 |
| 2026-03-28 12:00 |
18:30:14.34 |
+15:53:38.2 |
HIP 90669 |
4.69 |
| 2026-03-29 00:00 |
18:30:15.79 |
+15:55:07.6 |
HIP 90669 |
4.22 |
| 2026-03-29 12:00 |
18:30:17.16 |
+15:56:37.0 |
HIP 90669 |
4.26 |
| 2026-03-30 00:00 |
18:30:18.44 |
+15:58:06.4 |
HIP 90669 |
4.79 |
| 2026-03-30 12:00 |
18:30:19.64 |
+15:59:35.8 |
HIP 90669 |
5.67 |
| 2026-03-31 00:00 |
18:30:20.76 |
+16:01:05.1 |
HIP 90669 |
6.77 |
| 2026-03-31 12:00 |
18:30:21.79 |
+16:02:34.4 |
HIP 90669 |
7.99 |
| 2026-04-01 00:00 |
18:30:22.74 |
+16:04:03.6 |
HIP 90669 |
9.28 |
| 2026-04-01 12:00 |
18:30:23.61 |
+16:05:32.8 |
HIP 90669 |
10.61 |
| 2026-04-02 00:00 |
18:30:24.39 |
+16:07:01.9 |
HIP 90669 |
11.98 |
| 2026-04-02 12:00 |
18:30:25.09 |
+16:08:30.9 |
HIP 90669 |
13.36 |
| 2026-04-03 00:00 |
18:30:25.71 |
+16:10:00.0 |
HIP 90669 |
14.75 |
| 2026-04-03 12:00 |
18:30:26.24 |
+16:11:28.8 |
HIP 90669 |
16.16 |
| 2026-04-04 00:00 |
18:30:26.69 |
+16:12:57.7 |
HIP 90669 |
17.56 |
| 2026-04-04 12:00 |
18:30:27.05 |
+16:14:26.4 |
HIP 90669 |
18.97 |
| 2026-04-05 00:00 |
18:30:27.34 |
+16:15:55.0 |
HIP 90669 |
20.39 |
| 2026-04-05 12:00 |
18:30:27.53 |
+16:17:23.5 |
HIP 90669 |
21.80 |
| 2026-04-06 00:00 |
18:30:27.65 |
+16:18:52.0 |
HIP 90669 |
23.21 |
| 2026-04-06 12:00 |
18:30:27.68 |
+16:20:20.3 |
HIP 90669 |
24.63 |
| 2026-04-07 00:00 |
18:30:27.63 |
+16:21:48.4 |
HIP 90877 |
26.02 |
| 2026-04-07 12:00 |
18:30:27.49 |
+16:23:16.5 |
HIP 90877 |
25.92 |
| 2026-04-08 00:00 |
18:30:27.27 |
+16:24:44.4 |
HIP 90695 |
25.39 |
| 2026-04-08 12:00 |
18:30:26.97 |
+16:26:12.2 |
HIP 90695 |
23.93 |
| 2026-04-09 00:00 |
18:30:26.58 |
+16:27:39.8 |
HIP 90695 |
22.47 |
| 2026-04-09 12:00 |
18:30:26.11 |
+16:29:07.3 |
HIP 90695 |
21.01 |
| 2026-04-10 00:00 |
18:30:25.56 |
+16:30:34.6 |
HIP 90695 |
19.55 |
| 2026-04-10 12:00 |
18:30:24.92 |
+16:32:01.7 |
HIP 90695 |
18.09 |
| 2026-04-11 00:00 |
18:30:24.20 |
+16:33:28.6 |
HIP 90695 |
16.63 |
| 2026-04-11 12:00 |
18:30:23.39 |
+16:34:55.4 |
HIP 90695 |
15.17 |
| 2026-04-12 00:00 |
18:30:22.51 |
+16:36:22.0 |
HIP 90695 |
13.71 |
| 2026-04-12 12:00 |
18:30:21.54 |
+16:37:48.4 |
HIP 90695 |
12.26 |
| 2026-04-13 00:00 |
18:30:20.48 |
+16:39:14.6 |
HIP 90695 |
10.80 |
| 2026-04-13 12:00 |
18:30:19.34 |
+16:40:40.5 |
HIP 90695 |
9.35 |
| 2026-04-14 00:00 |
18:30:18.12 |
+16:42:06.3 |
HIP 90695 |
7.89 |
| 2026-04-14 12:00 |
18:30:16.82 |
+16:43:31.8 |
HIP 90695 |
6.45 |
| 2026-04-15 00:00 |
18:30:15.44 |
+16:44:57.1 |
HIP 90695 |
5.02 |
| 2026-04-15 12:00 |
18:30:13.97 |
+16:46:22.1 |
HIP 90695 |
3.61 |
| 2026-04-16 00:00 |
18:30:12.42 |
+16:47:46.9 |
HIP 90695 |
2.29 |