メタデータ
| 項目 |
値 |
| Designation |
257P/Catalina |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2013-06-04T09:54:55.097280Z |
| Orbit solution date (soln_date, UTC) |
2023-01-14T00:13:33Z |
| Obs used |
2118 |
| NEO |
- |
| M1 |
15.100 |
| K1 |
5.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2014-12-24.0000000 |
| e |
0.43237437 |
| q (au) |
2.130596 |
| a (au) |
3.753523 |
| i (deg) |
20.240315 |
| Ω (om, deg) |
207.850144 |
| ω (w, deg) |
117.883991 |
| M (ma, deg) |
76.926834 |
等級
散乱 + 全体線形
$$
M_a = (13.517 + 2.899\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
13.517 |
| n |
2.899 |
| gf |
0.999 |
| gb |
-0.502 |
| 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
ファインディングチャート
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
13:32:58.06 |
-08:22:29.5 |
HIP 66115 |
5.28 |
| 2026-09-20 12:00 |
13:33:31.27 |
-08:24:38.7 |
HIP 66137 |
1.77 |
| 2026-09-21 00:00 |
13:34:04.57 |
-08:26:48.3 |
HIP 66137 |
9.19 |
| 2026-09-21 12:00 |
13:34:37.94 |
-08:28:58.0 |
HIP 66252 |
8.56 |
| 2026-09-22 00:00 |
13:35:11.39 |
-08:31:07.9 |
HIP 66252 |
12.68 |
| 2026-09-22 12:00 |
13:35:44.92 |
-08:33:18.1 |
HIP 66252 |
19.88 |
| 2026-09-23 00:00 |
13:36:18.54 |
-08:35:28.5 |
HIP 66252 |
27.89 |
| 2026-09-23 12:00 |
13:36:52.22 |
-08:37:39.0 |
HIP 66560 |
29.46 |
| 2026-09-24 00:00 |
13:37:25.99 |
-08:39:49.7 |
HIP 66560 |
23.45 |
| 2026-09-24 12:00 |
13:37:59.83 |
-08:42:00.7 |
HIP 66560 |
19.51 |
| 2026-09-25 00:00 |
13:38:33.75 |
-08:44:11.7 |
HIP 66560 |
18.99 |
| 2026-09-25 12:00 |
13:39:07.75 |
-08:46:23.0 |
HIP 66560 |
22.17 |
| 2026-09-26 00:00 |
13:39:41.82 |
-08:48:34.4 |
HIP 66757 |
20.59 |
| 2026-09-26 12:00 |
13:40:15.97 |
-08:50:46.0 |
HIP 66757 |
14.82 |
| 2026-09-27 00:00 |
13:40:50.20 |
-08:52:57.7 |
HIP 66757 |
12.94 |
| 2026-09-27 12:00 |
13:41:24.50 |
-08:55:09.5 |
HIP 66803 |
13.33 |
| 2026-09-28 00:00 |
13:41:58.87 |
-08:57:21.5 |
HIP 66803 |
16.12 |
| 2026-09-28 12:00 |
13:42:33.32 |
-08:59:33.6 |
HIP 66803 |
22.29 |
| 2026-09-29 00:00 |
13:43:07.85 |
-09:01:45.8 |
HIP 66987 |
28.05 |
| 2026-09-29 12:00 |
13:43:42.44 |
-09:03:58.2 |
HIP 66987 |
24.55 |
| 2026-09-30 00:00 |
13:44:17.12 |
-09:06:10.6 |
HIP 66987 |
23.97 |
| 2026-09-30 12:00 |
13:44:51.86 |
-09:08:23.2 |
HIP 66987 |
26.51 |
| 2026-10-01 00:00 |
13:45:26.68 |
-09:10:35.8 |
HIP 67145 |
25.24 |
| 2026-10-01 12:00 |
13:46:01.58 |
-09:12:48.6 |
HIP 67145 |
23.64 |
| 2026-10-02 00:00 |
13:46:36.54 |
-09:15:01.4 |
HIP 67145 |
25.29 |
| 2026-10-02 12:00 |
13:47:11.58 |
-09:17:14.3 |
HIP 67271 |
25.33 |
| 2026-10-03 00:00 |
13:47:46.69 |
-09:19:27.3 |
HIP 67271 |
24.52 |
| 2026-10-03 12:00 |
13:48:21.87 |
-09:21:40.3 |
HIP 67471 |
20.90 |
| 2026-10-04 00:00 |
13:48:57.13 |
-09:23:53.4 |
HIP 67471 |
15.45 |
| 2026-10-04 12:00 |
13:49:32.45 |
-09:26:06.5 |
HIP 67471 |
14.22 |
| 2026-10-05 00:00 |
13:50:07.85 |
-09:28:19.7 |
HIP 67471 |
18.09 |
| 2026-10-05 12:00 |
13:50:43.32 |
-09:30:32.9 |
HIP 67471 |
24.81 |
| 2026-10-06 00:00 |
13:51:18.85 |
-09:32:46.2 |
HIP 67471 |
32.67 |
| 2026-10-06 12:00 |
13:51:54.46 |
-09:34:59.4 |
HIP 67471 |
41.04 |
| 2026-10-07 00:00 |
13:52:30.14 |
-09:37:12.7 |
HIP 67968 |
38.97 |
| 2026-10-07 12:00 |
13:53:05.88 |
-09:39:25.9 |
HIP 67968 |
30.47 |
| 2026-10-08 00:00 |
13:53:41.70 |
-09:41:39.2 |
HIP 67968 |
22.43 |
| 2026-10-08 12:00 |
13:54:17.58 |
-09:43:52.5 |
HIP 67968 |
15.58 |
| 2026-10-09 00:00 |
13:54:53.53 |
-09:46:05.7 |
HIP 67968 |
12.20 |
| 2026-10-09 12:00 |
13:55:29.54 |
-09:48:18.9 |
HIP 68038 |
6.54 |
| 2026-10-10 00:00 |
13:56:05.62 |
-09:50:32.1 |
HIP 68038 |
6.06 |
| 2026-10-10 12:00 |
13:56:41.77 |
-09:52:45.2 |
HIP 68107 |
9.37 |
| 2026-10-11 00:00 |
13:57:17.98 |
-09:54:58.3 |
HIP 68107 |
12.41 |