メタデータ
| 項目 |
値 |
| Designation |
208P/McMillan |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2016-07-02T01:58:31.463040Z |
| Orbit solution date (soln_date, UTC) |
2025-10-28T16:12:51Z |
| Obs used |
402 |
| NEO |
- |
| M1 |
16.100 |
| 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) |
2014-08-19.0000000 |
| e |
0.37204667 |
| q (au) |
2.543028 |
| a (au) |
4.049708 |
| i (deg) |
4.409401 |
| Ω (om, deg) |
36.427937 |
| ω (w, deg) |
310.603963 |
| M (ma, deg) |
277.388305 |
等級
散乱 + 全体線形
$$
M_a = (14.985 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
14.985 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.565 |
| 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 |
08:43:45.93 |
+22:07:35.5 |
HIP 42743 |
15.17 |
| 2026-09-20 12:00 |
08:44:10.24 |
+22:06:22.6 |
HIP 42927 |
18.20 |
| 2026-09-21 00:00 |
08:44:34.44 |
+22:05:10.1 |
HIP 42927 |
14.57 |
| 2026-09-21 12:00 |
08:44:58.52 |
+22:03:57.9 |
HIP 42927 |
12.61 |
| 2026-09-22 00:00 |
08:45:22.49 |
+22:02:46.1 |
HIP 42927 |
13.07 |
| 2026-09-22 12:00 |
08:45:46.34 |
+22:01:34.6 |
HIP 42927 |
15.71 |
| 2026-09-23 00:00 |
08:46:10.08 |
+22:00:23.5 |
HIP 42927 |
19.64 |
| 2026-09-23 12:00 |
08:46:33.70 |
+21:59:12.7 |
HIP 43078 |
21.95 |
| 2026-09-24 00:00 |
08:46:57.20 |
+21:58:02.4 |
HIP 43078 |
24.00 |
| 2026-09-24 12:00 |
08:47:20.58 |
+21:56:52.4 |
HIP 43078 |
27.05 |
| 2026-09-25 00:00 |
08:47:43.85 |
+21:55:42.8 |
HIP 43275 |
25.71 |
| 2026-09-25 12:00 |
08:48:06.99 |
+21:54:33.6 |
HIP 43259 |
22.72 |
| 2026-09-26 00:00 |
08:48:30.02 |
+21:53:24.8 |
HIP 43259 |
20.17 |
| 2026-09-26 12:00 |
08:48:52.92 |
+21:52:16.4 |
HIP 43259 |
18.90 |
| 2026-09-27 00:00 |
08:49:15.70 |
+21:51:08.4 |
HIP 43259 |
19.15 |
| 2026-09-27 12:00 |
08:49:38.36 |
+21:50:00.8 |
HIP 43259 |
20.83 |
| 2026-09-28 00:00 |
08:50:00.89 |
+21:48:53.7 |
HIP 43259 |
23.64 |
| 2026-09-28 12:00 |
08:50:23.31 |
+21:47:47.0 |
HIP 43538 |
26.35 |
| 2026-09-29 00:00 |
08:50:45.59 |
+21:46:40.7 |
HIP 43538 |
22.61 |
| 2026-09-29 12:00 |
08:51:07.75 |
+21:45:34.9 |
HIP 43538 |
19.62 |
| 2026-09-30 00:00 |
08:51:29.79 |
+21:44:29.5 |
HIP 43538 |
17.71 |
| 2026-09-30 12:00 |
08:51:51.69 |
+21:43:24.5 |
HIP 43538 |
17.24 |
| 2026-10-01 00:00 |
08:52:13.47 |
+21:42:20.0 |
HIP 43538 |
18.29 |
| 2026-10-01 12:00 |
08:52:35.12 |
+21:41:16.0 |
HIP 43538 |
20.59 |
| 2026-10-02 00:00 |
08:52:56.64 |
+21:40:12.5 |
HIP 43538 |
23.78 |
| 2026-10-02 12:00 |
08:53:18.03 |
+21:39:09.5 |
HIP 43538 |
27.52 |
| 2026-10-03 00:00 |
08:53:39.28 |
+21:38:06.9 |
HIP 43538 |
31.62 |
| 2026-10-03 12:00 |
08:54:00.41 |
+21:37:04.8 |
HIP 43855 |
27.91 |
| 2026-10-04 00:00 |
08:54:21.39 |
+21:36:03.3 |
HIP 43855 |
23.33 |
| 2026-10-04 12:00 |
08:54:42.25 |
+21:35:02.2 |
HIP 43855 |
18.98 |
| 2026-10-05 00:00 |
08:55:02.97 |
+21:34:01.7 |
HIP 43855 |
15.03 |
| 2026-10-05 12:00 |
08:55:23.55 |
+21:33:01.7 |
HIP 43855 |
11.84 |
| 2026-10-06 00:00 |
08:55:43.99 |
+21:32:02.2 |
HIP 43855 |
10.12 |
| 2026-10-06 12:00 |
08:56:04.29 |
+21:31:03.3 |
HIP 43855 |
10.55 |
| 2026-10-07 00:00 |
08:56:24.46 |
+21:30:04.9 |
HIP 43855 |
12.89 |
| 2026-10-07 12:00 |
08:56:44.48 |
+21:29:07.1 |
HIP 43985 |
12.64 |
| 2026-10-08 00:00 |
08:57:04.36 |
+21:28:09.8 |
HIP 43985 |
8.75 |
| 2026-10-08 12:00 |
08:57:24.09 |
+21:27:13.1 |
HIP 43985 |
6.19 |
| 2026-10-09 00:00 |
08:57:43.69 |
+21:26:17.0 |
HIP 43985 |
6.61 |
| 2026-10-09 12:00 |
08:58:03.13 |
+21:25:21.5 |
HIP 43985 |
9.60 |
| 2026-10-10 00:00 |
08:58:22.43 |
+21:24:26.5 |
HIP 43985 |
13.50 |
| 2026-10-10 12:00 |
08:58:41.59 |
+21:23:32.2 |
HIP 44097 |
13.95 |
| 2026-10-11 00:00 |
08:59:00.59 |
+21:22:38.4 |
HIP 44097 |
12.71 |