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) |
| 2026-07-29 00:00 |
06:47:55.29 |
-55:20:15.7 |
HIP 32565 |
3.59 |
| 2026-07-29 12:00 |
06:47:59.76 |
-55:20:35.3 |
HIP 32565 |
3.67 |
| 2026-07-30 00:00 |
06:48:04.22 |
-55:20:55.2 |
HIP 32565 |
3.87 |
| 2026-07-30 12:00 |
06:48:08.66 |
-55:21:15.5 |
HIP 32565 |
4.19 |
| 2026-07-31 00:00 |
06:48:13.08 |
-55:21:36.0 |
HIP 32565 |
4.58 |
| 2026-07-31 12:00 |
06:48:17.49 |
-55:21:56.8 |
HIP 32565 |
5.05 |
| 2026-08-01 00:00 |
06:48:21.87 |
-55:22:17.9 |
HIP 32565 |
5.56 |
| 2026-08-01 12:00 |
06:48:26.24 |
-55:22:39.3 |
HIP 32565 |
6.12 |
| 2026-08-02 00:00 |
06:48:30.59 |
-55:23:01.0 |
HIP 32565 |
6.70 |
| 2026-08-02 12:00 |
06:48:34.92 |
-55:23:23.0 |
HIP 32565 |
7.30 |
| 2026-08-03 00:00 |
06:48:39.24 |
-55:23:45.3 |
HIP 32565 |
7.92 |
| 2026-08-03 12:00 |
06:48:43.53 |
-55:24:07.9 |
HIP 32565 |
8.55 |
| 2026-08-04 00:00 |
06:48:47.80 |
-55:24:30.8 |
HIP 32565 |
9.19 |
| 2026-08-04 12:00 |
06:48:52.05 |
-55:24:54.0 |
HIP 32565 |
9.84 |
| 2026-08-05 00:00 |
06:48:56.29 |
-55:25:17.5 |
HIP 32565 |
10.49 |
| 2026-08-05 12:00 |
06:49:00.50 |
-55:25:41.2 |
HIP 32565 |
11.15 |
| 2026-08-06 00:00 |
06:49:04.69 |
-55:26:05.3 |
HIP 32565 |
11.82 |
| 2026-08-06 12:00 |
06:49:08.86 |
-55:26:29.6 |
HIP 32565 |
12.49 |
| 2026-08-07 00:00 |
06:49:13.01 |
-55:26:54.2 |
HIP 32565 |
13.16 |
| 2026-08-07 12:00 |
06:49:17.14 |
-55:27:19.1 |
HIP 32565 |
13.83 |
| 2026-08-08 00:00 |
06:49:21.24 |
-55:27:44.3 |
HIP 32565 |
14.51 |
| 2026-08-08 12:00 |
06:49:25.33 |
-55:28:09.8 |
HIP 32565 |
15.19 |
| 2026-08-09 00:00 |
06:49:29.39 |
-55:28:35.6 |
HIP 32565 |
15.87 |
| 2026-08-09 12:00 |
06:49:33.42 |
-55:29:01.6 |
HIP 32565 |
16.56 |
| 2026-08-10 00:00 |
06:49:37.44 |
-55:29:27.9 |
HIP 32820 |
16.86 |
| 2026-08-10 12:00 |
06:49:41.43 |
-55:29:54.5 |
HIP 32820 |
16.22 |
| 2026-08-11 00:00 |
06:49:45.40 |
-55:30:21.3 |
HIP 32820 |
15.58 |
| 2026-08-11 12:00 |
06:49:49.34 |
-55:30:48.5 |
HIP 32820 |
14.94 |
| 2026-08-12 00:00 |
06:49:53.26 |
-55:31:15.9 |
HIP 32820 |
14.31 |
| 2026-08-12 12:00 |
06:49:57.15 |
-55:31:43.6 |
HIP 32820 |
13.68 |
| 2026-08-13 00:00 |
06:50:01.02 |
-55:32:11.5 |
HIP 32820 |
13.06 |
| 2026-08-13 12:00 |
06:50:04.86 |
-55:32:39.7 |
HIP 32820 |
12.45 |
| 2026-08-14 00:00 |
06:50:08.68 |
-55:33:08.2 |
HIP 32820 |
11.84 |
| 2026-08-14 12:00 |
06:50:12.47 |
-55:33:36.9 |
HIP 32820 |
11.25 |
| 2026-08-15 00:00 |
06:50:16.23 |
-55:34:05.9 |
HIP 32820 |
10.66 |
| 2026-08-15 12:00 |
06:50:19.97 |
-55:34:35.2 |
HIP 32820 |
10.09 |
| 2026-08-16 00:00 |
06:50:23.69 |
-55:35:04.7 |
HIP 32820 |
9.54 |
| 2026-08-16 12:00 |
06:50:27.37 |
-55:35:34.4 |
HIP 32820 |
9.00 |
| 2026-08-17 00:00 |
06:50:31.03 |
-55:36:04.4 |
HIP 32820 |
8.49 |
| 2026-08-17 12:00 |
06:50:34.66 |
-55:36:34.7 |
HIP 32820 |
8.01 |
| 2026-08-18 00:00 |
06:50:38.26 |
-55:37:05.2 |
HIP 32820 |
7.56 |
| 2026-08-18 12:00 |
06:50:41.83 |
-55:37:36.0 |
HIP 32820 |
7.14 |
| 2026-08-19 00:00 |
06:50:45.38 |
-55:38:07.0 |
HIP 32820 |
6.78 |