メタデータ
| 項目 |
値 |
| Designation |
421P/McNaught |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2009-09-09T00:24:44.127360Z |
| Orbit solution date (soln_date, UTC) |
2023-04-24T23:44:12Z |
| Obs used |
96 |
| NEO |
- |
| M1 |
13.700 |
| K1 |
13.250 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2010-11-09.0000000 |
| e |
0.67538400 |
| q (au) |
1.649202 |
| a (au) |
5.080472 |
| i (deg) |
10.094478 |
| Ω (om, deg) |
55.683595 |
| ω (w, deg) |
259.900711 |
| M (ma, deg) |
36.664020 |
等級
散乱 + 全体線形
$$
M_a = (18.549 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
18.549 |
| n |
2.000 |
| gf |
0.986 |
| gb |
-0.500 |
| k |
0.830 |
| δ90 |
7.395 |
| 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) |
| 2026-06-01 00:00 |
08:44:30.82 |
+27:39:33.1 |
HIP 43048 |
23.25 |
| 2026-06-01 12:00 |
08:44:40.99 |
+27:38:31.3 |
HIP 43048 |
20.86 |
| 2026-06-02 00:00 |
08:44:51.25 |
+27:37:29.4 |
HIP 43048 |
18.49 |
| 2026-06-02 12:00 |
08:45:01.59 |
+27:36:27.2 |
HIP 43048 |
16.13 |
| 2026-06-03 00:00 |
08:45:12.02 |
+27:35:24.9 |
HIP 43048 |
13.81 |
| 2026-06-03 12:00 |
08:45:22.52 |
+27:34:22.4 |
HIP 43048 |
11.55 |
| 2026-06-04 00:00 |
08:45:33.10 |
+27:33:19.8 |
HIP 43048 |
9.44 |
| 2026-06-04 12:00 |
08:45:43.76 |
+27:32:17.0 |
HIP 43048 |
7.58 |
| 2026-06-05 00:00 |
08:45:54.50 |
+27:31:14.1 |
HIP 43048 |
6.26 |
| 2026-06-05 12:00 |
08:46:05.32 |
+27:30:11.0 |
HIP 43048 |
5.87 |
| 2026-06-06 00:00 |
08:46:16.21 |
+27:29:07.8 |
HIP 43048 |
6.58 |
| 2026-06-06 12:00 |
08:46:27.18 |
+27:28:04.4 |
HIP 43048 |
8.14 |
| 2026-06-07 00:00 |
08:46:38.23 |
+27:27:00.9 |
HIP 43048 |
10.17 |
| 2026-06-07 12:00 |
08:46:49.35 |
+27:25:57.2 |
HIP 43048 |
12.46 |
| 2026-06-08 00:00 |
08:47:00.55 |
+27:24:53.4 |
HIP 43048 |
14.90 |
| 2026-06-08 12:00 |
08:47:11.82 |
+27:23:49.4 |
HIP 43048 |
17.43 |
| 2026-06-09 00:00 |
08:47:23.16 |
+27:22:45.3 |
HIP 43048 |
20.02 |
| 2026-06-09 12:00 |
08:47:34.58 |
+27:21:41.1 |
HIP 43048 |
22.66 |
| 2026-06-10 00:00 |
08:47:46.07 |
+27:20:36.7 |
HIP 43048 |
25.34 |
| 2026-06-10 12:00 |
08:47:57.64 |
+27:19:32.2 |
HIP 43048 |
28.05 |
| 2026-06-11 00:00 |
08:48:09.27 |
+27:18:27.5 |
HIP 43048 |
30.78 |
| 2026-06-11 12:00 |
08:48:20.97 |
+27:17:22.8 |
HIP 43048 |
33.55 |
| 2026-06-12 00:00 |
08:48:32.75 |
+27:16:17.9 |
HIP 43048 |
36.33 |
| 2026-06-12 12:00 |
08:48:44.59 |
+27:15:12.8 |
HIP 43430 |
37.26 |
| 2026-06-13 00:00 |
08:48:56.50 |
+27:14:07.7 |
HIP 43430 |
34.60 |
| 2026-06-13 12:00 |
08:49:08.48 |
+27:13:02.4 |
HIP 43430 |
31.97 |
| 2026-06-14 00:00 |
08:49:20.53 |
+27:11:57.0 |
HIP 43430 |
29.37 |
| 2026-06-14 12:00 |
08:49:32.64 |
+27:10:51.5 |
HIP 43430 |
26.82 |
| 2026-06-15 00:00 |
08:49:44.82 |
+27:09:45.9 |
HIP 43430 |
24.35 |
| 2026-06-15 12:00 |
08:49:57.07 |
+27:08:40.2 |
HIP 43430 |
21.97 |
| 2026-06-16 00:00 |
08:50:09.38 |
+27:07:34.3 |
HIP 43430 |
19.74 |
| 2026-06-16 12:00 |
08:50:21.75 |
+27:06:28.4 |
HIP 43430 |
17.72 |
| 2026-06-17 00:00 |
08:50:34.19 |
+27:05:22.3 |
HIP 43430 |
15.98 |
| 2026-06-17 12:00 |
08:50:46.69 |
+27:04:16.2 |
HIP 43430 |
14.66 |
| 2026-06-18 00:00 |
08:50:59.25 |
+27:03:09.9 |
HIP 43430 |
13.86 |
| 2026-06-18 12:00 |
08:51:11.87 |
+27:02:03.6 |
HIP 43430 |
13.70 |
| 2026-06-19 00:00 |
08:51:24.55 |
+27:00:57.1 |
HIP 43430 |
14.21 |
| 2026-06-19 12:00 |
08:51:37.29 |
+26:59:50.6 |
HIP 43430 |
15.32 |
| 2026-06-20 00:00 |
08:51:50.09 |
+26:58:44.0 |
HIP 43430 |
16.92 |
| 2026-06-20 12:00 |
08:52:02.94 |
+26:57:37.3 |
HIP 43430 |
18.90 |
| 2026-06-21 00:00 |
08:52:15.86 |
+26:56:30.5 |
HIP 43670 |
21.04 |
| 2026-06-21 12:00 |
08:52:28.83 |
+26:55:23.6 |
HIP 43670 |
18.09 |
| 2026-06-22 00:00 |
08:52:41.85 |
+26:54:16.7 |
HIP 43670 |
15.19 |