メタデータ
| 項目 |
値 |
| Designation |
C/2008 A1 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2008-09-29T02:59:09.844800Z |
| Orbit solution date (soln_date, UTC) |
2021-04-16T12:07:02Z |
| Obs used |
906 |
| NEO |
- |
| M1 |
8.100 |
| K1 |
10.000 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2008-09-26.0000000 |
| e |
1.00023047 |
| q (au) |
1.073075 |
| a (au) |
-4655.992023 |
| i (deg) |
82.549175 |
| Ω (om, deg) |
277.883699 |
| ω (w, deg) |
348.473258 |
| M (ma, deg) |
-0.000010 |
等級
散乱 + 全体線形
$$
M_a = (10.584 + 3.102\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.584 |
| n |
3.102 |
| gf |
0.997 |
| gb |
-0.500 |
| k |
0.800 |
| δ90 |
8.389 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2008-01-10 |
2008-09-28 |
+4.7194 |
-3.531 |
| 2008-09-29 |
2008-11-02 |
+10.5269 |
-3.006 |
| 2008-11-02 |
2010-01-17 |
+3.3602 |
-1.676 |
log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
06:12:58.65 |
+53:42:46.2 |
HIP 29422 |
11.84 |
| 2026-05-12 12:00 |
06:13:02.57 |
+53:42:27.8 |
HIP 29422 |
12.49 |
| 2026-05-13 00:00 |
06:13:06.52 |
+53:42:09.6 |
HIP 29422 |
13.14 |
| 2026-05-13 12:00 |
06:13:10.49 |
+53:41:51.6 |
HIP 29422 |
13.79 |
| 2026-05-14 00:00 |
06:13:14.50 |
+53:41:33.7 |
HIP 29422 |
14.45 |
| 2026-05-14 12:00 |
06:13:18.52 |
+53:41:15.9 |
HIP 29422 |
15.10 |
| 2026-05-15 00:00 |
06:13:22.58 |
+53:40:58.3 |
HIP 29422 |
15.76 |
| 2026-05-15 12:00 |
06:13:26.66 |
+53:40:40.8 |
HIP 29422 |
16.43 |
| 2026-05-16 00:00 |
06:13:30.77 |
+53:40:23.5 |
HIP 29422 |
17.09 |
| 2026-05-16 12:00 |
06:13:34.90 |
+53:40:06.3 |
HIP 29422 |
17.76 |
| 2026-05-17 00:00 |
06:13:39.06 |
+53:39:49.3 |
HIP 29422 |
18.43 |
| 2026-05-17 12:00 |
06:13:43.24 |
+53:39:32.5 |
HIP 29422 |
19.10 |
| 2026-05-18 00:00 |
06:13:47.45 |
+53:39:15.8 |
HIP 29422 |
19.77 |
| 2026-05-18 12:00 |
06:13:51.68 |
+53:38:59.2 |
HIP 29422 |
20.45 |
| 2026-05-19 00:00 |
06:13:55.94 |
+53:38:42.8 |
HIP 29422 |
21.13 |
| 2026-05-19 12:00 |
06:14:00.22 |
+53:38:26.5 |
HIP 29422 |
21.81 |
| 2026-05-20 00:00 |
06:14:04.52 |
+53:38:10.4 |
HIP 29422 |
22.49 |
| 2026-05-20 12:00 |
06:14:08.84 |
+53:37:54.5 |
HIP 29795 |
21.84 |
| 2026-05-21 00:00 |
06:14:13.19 |
+53:37:38.7 |
HIP 29795 |
21.14 |
| 2026-05-21 12:00 |
06:14:17.56 |
+53:37:23.1 |
HIP 29795 |
20.45 |
| 2026-05-22 00:00 |
06:14:21.95 |
+53:37:07.6 |
HIP 29795 |
19.75 |
| 2026-05-22 12:00 |
06:14:26.36 |
+53:36:52.3 |
HIP 29795 |
19.05 |
| 2026-05-23 00:00 |
06:14:30.80 |
+53:36:37.1 |
HIP 29795 |
18.34 |
| 2026-05-23 12:00 |
06:14:35.25 |
+53:36:22.1 |
HIP 29795 |
17.64 |
| 2026-05-24 00:00 |
06:14:39.73 |
+53:36:07.3 |
HIP 29795 |
16.93 |
| 2026-05-24 12:00 |
06:14:44.22 |
+53:35:52.6 |
HIP 29795 |
16.22 |
| 2026-05-25 00:00 |
06:14:48.74 |
+53:35:38.1 |
HIP 29795 |
15.51 |
| 2026-05-25 12:00 |
06:14:53.27 |
+53:35:23.7 |
HIP 29795 |
14.80 |
| 2026-05-26 00:00 |
06:14:57.83 |
+53:35:09.5 |
HIP 29795 |
14.09 |
| 2026-05-26 12:00 |
06:15:02.40 |
+53:34:55.5 |
HIP 29795 |
13.37 |
| 2026-05-27 00:00 |
06:15:06.99 |
+53:34:41.6 |
HIP 29795 |
12.66 |
| 2026-05-27 12:00 |
06:15:11.60 |
+53:34:27.9 |
HIP 29795 |
11.95 |
| 2026-05-28 00:00 |
06:15:16.23 |
+53:34:14.4 |
HIP 29795 |
11.23 |
| 2026-05-28 12:00 |
06:15:20.88 |
+53:34:01.0 |
HIP 29795 |
10.52 |
| 2026-05-29 00:00 |
06:15:25.54 |
+53:33:47.8 |
HIP 29795 |
9.80 |
| 2026-05-29 12:00 |
06:15:30.22 |
+53:33:34.8 |
HIP 29795 |
9.09 |
| 2026-05-30 00:00 |
06:15:34.92 |
+53:33:21.9 |
HIP 29795 |
8.38 |
| 2026-05-30 12:00 |
06:15:39.64 |
+53:33:09.1 |
HIP 29795 |
7.67 |
| 2026-05-31 00:00 |
06:15:44.37 |
+53:32:56.6 |
HIP 29795 |
6.96 |
| 2026-05-31 12:00 |
06:15:49.11 |
+53:32:44.2 |
HIP 29795 |
6.26 |
| 2026-06-01 00:00 |
06:15:53.88 |
+53:32:32.0 |
HIP 29795 |
5.57 |
| 2026-06-01 12:00 |
06:15:58.66 |
+53:32:19.9 |
HIP 29795 |
4.90 |
| 2026-06-02 00:00 |
06:16:03.45 |
+53:32:08.0 |
HIP 29795 |
4.24 |