メタデータ
| 項目 |
値 |
| Designation |
C/2021 K3 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2022-02-02T08:11:00.119040Z |
| Orbit solution date (soln_date, UTC) |
2022-06-07T21:45:11Z |
| Obs used |
99 |
| NEO |
- |
| M1 |
14.500 |
| K1 |
4.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2021-07-16.0000000 |
| e |
1.00356145 |
| q (au) |
5.230100 |
| a (au) |
-1468.531415 |
| i (deg) |
134.804408 |
| Ω (om, deg) |
114.441510 |
| ω (w, deg) |
181.948465 |
| M (ma, deg) |
-0.003526 |
等級
散乱 + 全体線形
$$
M_a = (17.424 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
17.424 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.757 |
| 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 |
11:12:09.73 |
-49:06:52.1 |
HIP 54746 |
3.92 |
| 2026-03-26 12:00 |
11:11:51.76 |
-49:05:03.2 |
HIP 54746 |
6.85 |
| 2026-03-27 00:00 |
11:11:33.87 |
-49:03:13.2 |
HIP 54746 |
10.12 |
| 2026-03-27 12:00 |
11:11:16.05 |
-49:01:22.1 |
HIP 54670 |
10.44 |
| 2026-03-28 00:00 |
11:10:58.30 |
-48:59:29.9 |
HIP 54670 |
9.67 |
| 2026-03-28 12:00 |
11:10:40.62 |
-48:57:36.6 |
HIP 54670 |
10.08 |
| 2026-03-29 00:00 |
11:10:23.02 |
-48:55:42.2 |
HIP 54670 |
11.55 |
| 2026-03-29 12:00 |
11:10:05.50 |
-48:53:46.7 |
HIP 54670 |
13.74 |
| 2026-03-30 00:00 |
11:09:48.05 |
-48:51:50.2 |
HIP 54535 |
14.15 |
| 2026-03-30 12:00 |
11:09:30.68 |
-48:49:52.7 |
HIP 54535 |
12.14 |
| 2026-03-31 00:00 |
11:09:13.40 |
-48:47:54.1 |
HIP 54535 |
10.87 |
| 2026-03-31 12:00 |
11:08:56.19 |
-48:45:54.5 |
HIP 54535 |
10.62 |
| 2026-04-01 00:00 |
11:08:39.07 |
-48:43:53.9 |
HIP 54535 |
11.44 |
| 2026-04-01 12:00 |
11:08:22.04 |
-48:41:52.2 |
HIP 54380 |
8.63 |
| 2026-04-02 00:00 |
11:08:05.09 |
-48:39:49.6 |
HIP 54380 |
5.31 |
| 2026-04-02 12:00 |
11:07:48.23 |
-48:37:46.0 |
HIP 54380 |
2.41 |
| 2026-04-03 00:00 |
11:07:31.45 |
-48:35:41.4 |
HIP 54380 |
2.75 |
| 2026-04-03 12:00 |
11:07:14.76 |
-48:33:35.9 |
HIP 54380 |
5.77 |
| 2026-04-04 00:00 |
11:06:58.17 |
-48:31:29.4 |
HIP 54380 |
9.12 |
| 2026-04-04 12:00 |
11:06:41.67 |
-48:29:22.0 |
HIP 54380 |
12.53 |
| 2026-04-05 00:00 |
11:06:25.26 |
-48:27:13.7 |
HIP 54380 |
15.96 |
| 2026-04-05 12:00 |
11:06:08.94 |
-48:25:04.4 |
HIP 54180 |
17.70 |
| 2026-04-06 00:00 |
11:05:52.72 |
-48:22:54.3 |
HIP 54180 |
14.30 |
| 2026-04-06 12:00 |
11:05:36.59 |
-48:20:43.2 |
HIP 54180 |
10.93 |
| 2026-04-07 00:00 |
11:05:20.57 |
-48:18:31.3 |
HIP 54180 |
7.65 |
| 2026-04-07 12:00 |
11:05:04.64 |
-48:16:18.5 |
HIP 54180 |
4.60 |
| 2026-04-08 00:00 |
11:04:48.81 |
-48:14:04.9 |
HIP 54180 |
2.75 |
| 2026-04-08 12:00 |
11:04:33.08 |
-48:11:50.4 |
HIP 54180 |
4.21 |
| 2026-04-09 00:00 |
11:04:17.45 |
-48:09:35.1 |
HIP 54180 |
7.18 |
| 2026-04-09 12:00 |
11:04:01.93 |
-48:07:19.0 |
HIP 54180 |
10.43 |
| 2026-04-10 00:00 |
11:03:46.51 |
-48:05:02.0 |
HIP 54180 |
13.78 |
| 2026-04-10 12:00 |
11:03:31.19 |
-48:02:44.3 |
HIP 54180 |
17.15 |
| 2026-04-11 00:00 |
11:03:15.98 |
-48:00:25.8 |
HIP 54180 |
20.54 |
| 2026-04-11 12:00 |
11:03:00.88 |
-47:58:06.6 |
HIP 54137 |
23.06 |
| 2026-04-12 00:00 |
11:02:45.89 |
-47:55:46.5 |
HIP 54137 |
23.22 |
| 2026-04-12 12:00 |
11:02:31.00 |
-47:53:25.8 |
HIP 54137 |
23.86 |
| 2026-04-13 00:00 |
11:02:16.22 |
-47:51:04.3 |
HIP 54137 |
24.93 |
| 2026-04-13 12:00 |
11:02:01.56 |
-47:48:42.1 |
HIP 54137 |
26.40 |
| 2026-04-14 00:00 |
11:01:47.00 |
-47:46:19.2 |
HIP 54137 |
28.19 |
| 2026-04-14 12:00 |
11:01:32.56 |
-47:43:55.6 |
HIP 53714 |
26.22 |
| 2026-04-15 00:00 |
11:01:18.23 |
-47:41:31.3 |
HIP 53714 |
22.87 |
| 2026-04-15 12:00 |
11:01:04.02 |
-47:39:06.4 |
HIP 53714 |
19.55 |
| 2026-04-16 00:00 |
11:00:49.92 |
-47:36:40.8 |
HIP 53714 |
16.27 |