メタデータ
| 項目 |
値 |
| Designation |
P/2012 O2 (McNaught) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-06-25T02:23:11.711040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:20Z |
| Obs used |
81 |
| NEO |
- |
| M1 |
17.300 |
| K1 |
10.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2012-07-31.0000000 |
| e |
0.53827101 |
| q (au) |
1.660834 |
| a (au) |
3.596989 |
| i (deg) |
24.527455 |
| Ω (om, deg) |
120.813582 |
| ω (w, deg) |
183.047391 |
| M (ma, deg) |
5.186765 |
等級
散乱 + 全体線形
$$
M_a = (17.976 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
17.976 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.851 |
| 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
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) |
| 2026-07-29 00:00 |
02:33:30.39 |
-12:02:45.3 |
HIP 11861 |
6.60 |
| 2026-07-29 12:00 |
02:34:12.25 |
-12:06:33.1 |
HIP 11939 |
9.31 |
| 2026-07-30 00:00 |
02:34:53.75 |
-12:10:23.4 |
HIP 11939 |
13.43 |
| 2026-07-30 12:00 |
02:35:34.88 |
-12:14:16.3 |
HIP 12139 |
11.93 |
| 2026-07-31 00:00 |
02:36:15.64 |
-12:18:11.7 |
HIP 12139 |
3.35 |
| 2026-07-31 12:00 |
02:36:56.03 |
-12:22:09.8 |
HIP 12139 |
10.41 |
| 2026-08-01 00:00 |
02:37:36.04 |
-12:26:10.3 |
HIP 12139 |
20.72 |
| 2026-08-01 12:00 |
02:38:15.67 |
-12:30:13.4 |
HIP 12139 |
31.13 |
| 2026-08-02 00:00 |
02:38:54.92 |
-12:34:19.0 |
HIP 12341 |
25.84 |
| 2026-08-02 12:00 |
02:39:33.78 |
-12:38:27.2 |
HIP 12341 |
23.69 |
| 2026-08-03 00:00 |
02:40:12.26 |
-12:42:37.9 |
HIP 12539 |
19.42 |
| 2026-08-03 12:00 |
02:40:50.36 |
-12:46:51.1 |
HIP 12539 |
15.76 |
| 2026-08-04 00:00 |
02:41:28.06 |
-12:51:06.8 |
HIP 12539 |
18.14 |
| 2026-08-04 12:00 |
02:42:05.36 |
-12:55:24.9 |
HIP 12539 |
24.80 |
| 2026-08-05 00:00 |
02:42:42.28 |
-12:59:45.6 |
HIP 12539 |
33.19 |
| 2026-08-05 12:00 |
02:43:18.79 |
-13:04:08.7 |
HIP 12774 |
36.83 |
| 2026-08-06 00:00 |
02:43:54.90 |
-13:08:34.3 |
HIP 12774 |
39.23 |
| 2026-08-06 12:00 |
02:44:30.60 |
-13:13:02.3 |
HIP 12981 |
36.66 |
| 2026-08-07 00:00 |
02:45:05.90 |
-13:17:32.8 |
HIP 12981 |
27.46 |
| 2026-08-07 12:00 |
02:45:40.79 |
-13:22:05.7 |
HIP 12981 |
18.89 |
| 2026-08-08 00:00 |
02:46:15.26 |
-13:26:41.0 |
HIP 12981 |
12.14 |
| 2026-08-08 12:00 |
02:46:49.32 |
-13:31:18.6 |
HIP 12981 |
11.04 |
| 2026-08-09 00:00 |
02:47:22.96 |
-13:35:58.6 |
HIP 12981 |
16.63 |
| 2026-08-09 12:00 |
02:47:56.18 |
-13:40:41.0 |
HIP 12983 |
21.85 |
| 2026-08-10 00:00 |
02:48:28.97 |
-13:45:25.7 |
HIP 13207 |
22.28 |
| 2026-08-10 12:00 |
02:49:01.33 |
-13:50:12.7 |
HIP 13207 |
13.78 |
| 2026-08-11 00:00 |
02:49:33.27 |
-13:55:02.0 |
HIP 13207 |
7.37 |
| 2026-08-11 12:00 |
02:50:04.77 |
-13:59:53.5 |
HIP 13207 |
9.26 |
| 2026-08-12 00:00 |
02:50:35.84 |
-14:04:47.3 |
HIP 13207 |
16.75 |
| 2026-08-12 12:00 |
02:51:06.48 |
-14:09:43.3 |
HIP 13207 |
25.19 |
| 2026-08-13 00:00 |
02:51:36.67 |
-14:14:41.4 |
HIP 13470 |
27.22 |
| 2026-08-13 12:00 |
02:52:06.42 |
-14:19:41.7 |
HIP 13470 |
20.40 |
| 2026-08-14 00:00 |
02:52:35.72 |
-14:24:44.2 |
HIP 13470 |
15.78 |
| 2026-08-14 12:00 |
02:53:04.58 |
-14:29:48.7 |
HIP 13470 |
15.36 |
| 2026-08-15 00:00 |
02:53:32.99 |
-14:34:55.3 |
HIP 13470 |
19.31 |
| 2026-08-15 12:00 |
02:54:00.95 |
-14:40:03.9 |
HIP 13470 |
25.63 |
| 2026-08-16 00:00 |
02:54:28.46 |
-14:45:14.5 |
HIP 13470 |
32.93 |
| 2026-08-16 12:00 |
02:54:55.51 |
-14:50:27.1 |
HIP 13705 |
24.94 |
| 2026-08-17 00:00 |
02:55:22.10 |
-14:55:41.6 |
HIP 13705 |
17.00 |
| 2026-08-17 12:00 |
02:55:48.24 |
-15:00:58.0 |
HIP 13705 |
9.78 |
| 2026-08-18 00:00 |
02:56:13.91 |
-15:06:16.3 |
HIP 13705 |
6.24 |
| 2026-08-18 12:00 |
02:56:39.12 |
-15:11:36.4 |
HIP 13705 |
10.74 |
| 2026-08-19 00:00 |
02:57:03.87 |
-15:16:58.4 |
HIP 13705 |
17.93 |