メタデータ
| 項目 |
値 |
| Designation |
318P/McNaught-Hartley |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2015-10-21T00:27:13.642560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:23Z |
| Obs used |
442 |
| NEO |
- |
| M1 |
9.600 |
| K1 |
13.500 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2012-04-13.0000000 |
| e |
0.67524420 |
| q (au) |
2.445459 |
| a (au) |
7.530148 |
| i (deg) |
17.894853 |
| Ω (om, deg) |
35.754310 |
| ω (w, deg) |
313.177220 |
| M (ma, deg) |
298.659661 |
等級
散乱 + 全体線形
$$
M_a = (10.986 + 4.792\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.986 |
| n |
4.792 |
| gf |
0.995 |
| gb |
-0.500 |
| k |
0.800 |
| δ90 |
2.292 |
| 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) |
| 2026-07-29 00:00 |
11:39:16.76 |
+15:03:53.8 |
HIP 56810 |
22.55 |
| 2026-07-29 12:00 |
11:39:23.52 |
+15:02:45.3 |
HIP 56810 |
24.20 |
| 2026-07-30 00:00 |
11:39:30.33 |
+15:01:36.8 |
HIP 56807 |
25.06 |
| 2026-07-30 12:00 |
11:39:37.18 |
+15:00:28.2 |
HIP 56807 |
24.85 |
| 2026-07-31 00:00 |
11:39:44.08 |
+14:59:19.4 |
HIP 56807 |
24.80 |
| 2026-07-31 12:00 |
11:39:51.03 |
+14:58:10.5 |
HIP 56807 |
24.92 |
| 2026-08-01 00:00 |
11:39:58.01 |
+14:57:01.6 |
HIP 56807 |
25.21 |
| 2026-08-01 12:00 |
11:40:05.05 |
+14:55:52.5 |
HIP 56807 |
25.67 |
| 2026-08-02 00:00 |
11:40:12.12 |
+14:54:43.4 |
HIP 56807 |
26.29 |
| 2026-08-02 12:00 |
11:40:19.24 |
+14:53:34.1 |
HIP 56807 |
27.06 |
| 2026-08-03 00:00 |
11:40:26.40 |
+14:52:24.8 |
HIP 56807 |
27.98 |
| 2026-08-03 12:00 |
11:40:33.61 |
+14:51:15.4 |
HIP 57068 |
27.83 |
| 2026-08-04 00:00 |
11:40:40.86 |
+14:50:05.8 |
HIP 57068 |
25.77 |
| 2026-08-04 12:00 |
11:40:48.14 |
+14:48:56.2 |
HIP 57068 |
23.70 |
| 2026-08-05 00:00 |
11:40:55.48 |
+14:47:46.6 |
HIP 57068 |
21.64 |
| 2026-08-05 12:00 |
11:41:02.85 |
+14:46:36.8 |
HIP 57068 |
19.58 |
| 2026-08-06 00:00 |
11:41:10.26 |
+14:45:27.0 |
HIP 57068 |
17.53 |
| 2026-08-06 12:00 |
11:41:17.71 |
+14:44:17.1 |
HIP 57068 |
15.50 |
| 2026-08-07 00:00 |
11:41:25.21 |
+14:43:07.1 |
HIP 57068 |
13.49 |
| 2026-08-07 12:00 |
11:41:32.74 |
+14:41:57.1 |
HIP 57068 |
11.54 |
| 2026-08-08 00:00 |
11:41:40.31 |
+14:40:47.0 |
HIP 57068 |
9.67 |
| 2026-08-08 12:00 |
11:41:47.92 |
+14:39:36.8 |
HIP 57068 |
7.95 |
| 2026-08-09 00:00 |
11:41:55.57 |
+14:38:26.6 |
HIP 57068 |
6.51 |
| 2026-08-09 12:00 |
11:42:03.26 |
+14:37:16.3 |
HIP 57068 |
5.58 |
| 2026-08-10 00:00 |
11:42:10.99 |
+14:36:06.0 |
HIP 57068 |
5.45 |
| 2026-08-10 12:00 |
11:42:18.75 |
+14:34:55.6 |
HIP 57068 |
6.17 |
| 2026-08-11 00:00 |
11:42:26.55 |
+14:33:45.2 |
HIP 57068 |
7.51 |
| 2026-08-11 12:00 |
11:42:34.39 |
+14:32:34.8 |
HIP 57068 |
9.20 |
| 2026-08-12 00:00 |
11:42:42.26 |
+14:31:24.3 |
HIP 57068 |
11.10 |
| 2026-08-12 12:00 |
11:42:50.17 |
+14:30:13.8 |
HIP 57068 |
13.11 |
| 2026-08-13 00:00 |
11:42:58.11 |
+14:29:03.2 |
HIP 57068 |
15.20 |
| 2026-08-13 12:00 |
11:43:06.09 |
+14:27:52.6 |
HIP 57068 |
17.34 |
| 2026-08-14 00:00 |
11:43:14.10 |
+14:26:42.0 |
HIP 57068 |
19.51 |
| 2026-08-14 12:00 |
11:43:22.15 |
+14:25:31.4 |
HIP 57068 |
21.72 |
| 2026-08-15 00:00 |
11:43:30.23 |
+14:24:20.8 |
HIP 57068 |
23.94 |
| 2026-08-15 12:00 |
11:43:38.34 |
+14:23:10.1 |
HIP 57320 |
23.73 |
| 2026-08-16 00:00 |
11:43:46.49 |
+14:21:59.5 |
HIP 57320 |
21.49 |
| 2026-08-16 12:00 |
11:43:54.67 |
+14:20:48.8 |
HIP 57320 |
19.27 |
| 2026-08-17 00:00 |
11:44:02.88 |
+14:19:38.1 |
HIP 57320 |
17.05 |
| 2026-08-17 12:00 |
11:44:11.12 |
+14:18:27.5 |
HIP 57320 |
14.86 |
| 2026-08-18 00:00 |
11:44:19.39 |
+14:17:16.8 |
HIP 57320 |
12.70 |
| 2026-08-18 12:00 |
11:44:27.69 |
+14:16:06.2 |
HIP 57320 |
10.61 |
| 2026-08-19 00:00 |
11:44:36.02 |
+14:14:55.5 |
HIP 57320 |
8.63 |