メタデータ
| 項目 |
値 |
| Designation |
C/2008 J4 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2008-06-19T09:29:06.619200Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:19Z |
| Obs used |
22 |
| NEO |
- |
| M1 |
16.500 |
| K1 |
12.750 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2008-05-17.0000000 |
| e |
1.00771428 |
| q (au) |
0.449265 |
| a (au) |
-58.238132 |
| i (deg) |
87.477450 |
| Ω (om, deg) |
289.372326 |
| ω (w, deg) |
93.055804 |
| M (ma, deg) |
-0.074059 |
等級
散乱 + 全体線形
$$
M_a = (16.126 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
16.126 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.885 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
06:36:03.65 |
-55:36:02.2 |
HIP 31661 |
20.23 |
| 2026-05-12 12:00 |
06:36:07.07 |
-55:35:32.2 |
HIP 31661 |
19.54 |
| 2026-05-13 00:00 |
06:36:10.53 |
-55:35:02.5 |
HIP 31661 |
18.85 |
| 2026-05-13 12:00 |
06:36:14.01 |
-55:34:33.0 |
HIP 31661 |
18.15 |
| 2026-05-14 00:00 |
06:36:17.53 |
-55:34:03.8 |
HIP 31661 |
17.46 |
| 2026-05-14 12:00 |
06:36:21.07 |
-55:33:34.8 |
HIP 31661 |
16.77 |
| 2026-05-15 00:00 |
06:36:24.64 |
-55:33:06.1 |
HIP 31661 |
16.08 |
| 2026-05-15 12:00 |
06:36:28.24 |
-55:32:37.6 |
HIP 31661 |
15.39 |
| 2026-05-16 00:00 |
06:36:31.87 |
-55:32:09.5 |
HIP 31661 |
14.70 |
| 2026-05-16 12:00 |
06:36:35.53 |
-55:31:41.5 |
HIP 31661 |
14.02 |
| 2026-05-17 00:00 |
06:36:39.21 |
-55:31:13.9 |
HIP 31661 |
13.33 |
| 2026-05-17 12:00 |
06:36:42.92 |
-55:30:46.5 |
HIP 31661 |
12.65 |
| 2026-05-18 00:00 |
06:36:46.66 |
-55:30:19.4 |
HIP 31661 |
11.97 |
| 2026-05-18 12:00 |
06:36:50.42 |
-55:29:52.5 |
HIP 31661 |
11.30 |
| 2026-05-19 00:00 |
06:36:54.21 |
-55:29:26.0 |
HIP 31661 |
10.63 |
| 2026-05-19 12:00 |
06:36:58.03 |
-55:28:59.7 |
HIP 31661 |
9.97 |
| 2026-05-20 00:00 |
06:37:01.88 |
-55:28:33.6 |
HIP 31661 |
9.31 |
| 2026-05-20 12:00 |
06:37:05.74 |
-55:28:07.9 |
HIP 31661 |
8.66 |
| 2026-05-21 00:00 |
06:37:09.64 |
-55:27:42.5 |
HIP 31661 |
8.02 |
| 2026-05-21 12:00 |
06:37:13.56 |
-55:27:17.3 |
HIP 31661 |
7.40 |
| 2026-05-22 00:00 |
06:37:17.50 |
-55:26:52.4 |
HIP 31661 |
6.79 |
| 2026-05-22 12:00 |
06:37:21.47 |
-55:26:27.8 |
HIP 31661 |
6.20 |
| 2026-05-23 00:00 |
06:37:25.46 |
-55:26:03.4 |
HIP 31661 |
5.64 |
| 2026-05-23 12:00 |
06:37:29.48 |
-55:25:39.4 |
HIP 31661 |
5.12 |
| 2026-05-24 00:00 |
06:37:33.51 |
-55:25:15.7 |
HIP 31661 |
4.65 |
| 2026-05-24 12:00 |
06:37:37.58 |
-55:24:52.2 |
HIP 31661 |
4.25 |
| 2026-05-25 00:00 |
06:37:41.66 |
-55:24:29.0 |
HIP 31661 |
3.93 |
| 2026-05-25 12:00 |
06:37:45.77 |
-55:24:06.2 |
HIP 31661 |
3.73 |
| 2026-05-26 00:00 |
06:37:49.90 |
-55:23:43.6 |
HIP 31661 |
3.66 |
| 2026-05-26 12:00 |
06:37:54.05 |
-55:23:21.3 |
HIP 31661 |
3.72 |
| 2026-05-27 00:00 |
06:37:58.22 |
-55:22:59.3 |
HIP 31661 |
3.92 |
| 2026-05-27 12:00 |
06:38:02.41 |
-55:22:37.6 |
HIP 31661 |
4.23 |
| 2026-05-28 00:00 |
06:38:06.63 |
-55:22:16.2 |
HIP 31661 |
4.63 |
| 2026-05-28 12:00 |
06:38:10.86 |
-55:21:55.1 |
HIP 31661 |
5.09 |
| 2026-05-29 00:00 |
06:38:15.12 |
-55:21:34.3 |
HIP 31661 |
5.61 |
| 2026-05-29 12:00 |
06:38:19.39 |
-55:21:13.8 |
HIP 31661 |
6.17 |
| 2026-05-30 00:00 |
06:38:23.69 |
-55:20:53.6 |
HIP 31804 |
5.69 |
| 2026-05-30 12:00 |
06:38:28.01 |
-55:20:33.7 |
HIP 31804 |
4.99 |
| 2026-05-31 00:00 |
06:38:32.34 |
-55:20:14.1 |
HIP 31804 |
4.30 |
| 2026-05-31 12:00 |
06:38:36.69 |
-55:19:54.9 |
HIP 31804 |
3.60 |
| 2026-06-01 00:00 |
06:38:41.07 |
-55:19:35.9 |
HIP 31804 |
2.91 |
| 2026-06-01 12:00 |
06:38:45.46 |
-55:19:17.2 |
HIP 31804 |
2.22 |
| 2026-06-02 00:00 |
06:38:49.87 |
-55:18:58.9 |
HIP 31804 |
1.55 |