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
$$
M_a = (18.570 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
18.570 |
| n |
2.000 |
| gf |
0.971 |
| gb |
-0.500 |
| k |
0.825 |
| δ90 |
7.163 |
| 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) |
| 2026-03-26 00:00 |
08:38:13.62 |
+29:14:07.7 |
HIP 42371 |
23.92 |
| 2026-03-26 12:00 |
08:38:07.96 |
+29:13:54.0 |
HIP 42371 |
24.26 |
| 2026-03-27 00:00 |
08:38:02.43 |
+29:13:39.6 |
HIP 42371 |
24.66 |
| 2026-03-27 12:00 |
08:37:57.04 |
+29:13:24.7 |
HIP 42371 |
25.12 |
| 2026-03-28 00:00 |
08:37:51.78 |
+29:13:09.3 |
HIP 42371 |
25.63 |
| 2026-03-28 12:00 |
08:37:46.65 |
+29:12:53.2 |
HIP 42185 |
24.95 |
| 2026-03-29 00:00 |
08:37:41.66 |
+29:12:36.6 |
HIP 42185 |
23.85 |
| 2026-03-29 12:00 |
08:37:36.80 |
+29:12:19.4 |
HIP 42185 |
22.78 |
| 2026-03-30 00:00 |
08:37:32.07 |
+29:12:01.7 |
HIP 42185 |
21.72 |
| 2026-03-30 12:00 |
08:37:27.48 |
+29:11:43.3 |
HIP 42185 |
20.69 |
| 2026-03-31 00:00 |
08:37:23.03 |
+29:11:24.5 |
HIP 42185 |
19.69 |
| 2026-03-31 12:00 |
08:37:18.70 |
+29:11:05.1 |
HIP 42185 |
18.70 |
| 2026-04-01 00:00 |
08:37:14.51 |
+29:10:45.1 |
HIP 42185 |
17.74 |
| 2026-04-01 12:00 |
08:37:10.46 |
+29:10:24.6 |
HIP 42185 |
16.80 |
| 2026-04-02 00:00 |
08:37:06.54 |
+29:10:03.5 |
HIP 42185 |
15.88 |
| 2026-04-02 12:00 |
08:37:02.76 |
+29:09:42.0 |
HIP 42185 |
14.99 |
| 2026-04-03 00:00 |
08:36:59.11 |
+29:09:19.9 |
HIP 42185 |
14.12 |
| 2026-04-03 12:00 |
08:36:55.59 |
+29:08:57.2 |
HIP 42185 |
13.26 |
| 2026-04-04 00:00 |
08:36:52.21 |
+29:08:34.0 |
HIP 42185 |
12.43 |
| 2026-04-04 12:00 |
08:36:48.97 |
+29:08:10.3 |
HIP 42185 |
11.62 |
| 2026-04-05 00:00 |
08:36:45.86 |
+29:07:46.1 |
HIP 42185 |
10.83 |
| 2026-04-05 12:00 |
08:36:42.88 |
+29:07:21.4 |
HIP 42185 |
10.06 |
| 2026-04-06 00:00 |
08:36:40.04 |
+29:06:56.2 |
HIP 42185 |
9.31 |
| 2026-04-06 12:00 |
08:36:37.33 |
+29:06:30.4 |
HIP 42185 |
8.59 |
| 2026-04-07 00:00 |
08:36:34.77 |
+29:06:04.2 |
HIP 42185 |
7.88 |
| 2026-04-07 12:00 |
08:36:32.33 |
+29:05:37.4 |
HIP 42185 |
7.20 |
| 2026-04-08 00:00 |
08:36:30.03 |
+29:05:10.2 |
HIP 42185 |
6.54 |
| 2026-04-08 12:00 |
08:36:27.87 |
+29:04:42.5 |
HIP 42185 |
5.91 |
| 2026-04-09 00:00 |
08:36:25.84 |
+29:04:14.2 |
HIP 42185 |
5.31 |
| 2026-04-09 12:00 |
08:36:23.94 |
+29:03:45.5 |
HIP 42185 |
4.74 |
| 2026-04-10 00:00 |
08:36:22.18 |
+29:03:16.3 |
HIP 42185 |
4.22 |
| 2026-04-10 12:00 |
08:36:20.56 |
+29:02:46.6 |
HIP 42185 |
3.77 |
| 2026-04-11 00:00 |
08:36:19.07 |
+29:02:16.5 |
HIP 42185 |
3.38 |
| 2026-04-11 12:00 |
08:36:17.72 |
+29:01:45.9 |
HIP 42185 |
3.10 |
| 2026-04-12 00:00 |
08:36:16.50 |
+29:01:14.8 |
HIP 42185 |
2.94 |
| 2026-04-12 12:00 |
08:36:15.41 |
+29:00:43.2 |
HIP 42185 |
2.92 |
| 2026-04-13 00:00 |
08:36:14.46 |
+29:00:11.2 |
HIP 42185 |
3.05 |
| 2026-04-13 12:00 |
08:36:13.65 |
+28:59:38.7 |
HIP 42185 |
3.29 |
| 2026-04-14 00:00 |
08:36:12.97 |
+28:59:05.7 |
HIP 42185 |
3.63 |
| 2026-04-14 12:00 |
08:36:12.42 |
+28:58:32.3 |
HIP 42185 |
4.05 |
| 2026-04-15 00:00 |
08:36:12.01 |
+28:57:58.5 |
HIP 42185 |
4.51 |
| 2026-04-15 12:00 |
08:36:11.73 |
+28:57:24.2 |
HIP 42185 |
5.02 |
| 2026-04-16 00:00 |
08:36:11.59 |
+28:56:49.4 |
HIP 42185 |
5.55 |