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 |
0.998 |
| gb |
-0.500 |
| k |
0.800 |
| δ90 |
8.390 |
| 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) |
| 2026-07-29 00:00 |
06:25:29.68 |
+53:28:53.1 |
HIP 30610 |
16.56 |
| 2026-07-29 12:00 |
06:25:34.12 |
+53:29:01.5 |
HIP 30610 |
16.26 |
| 2026-07-30 00:00 |
06:25:38.54 |
+53:29:10.1 |
HIP 30610 |
15.98 |
| 2026-07-30 12:00 |
06:25:42.93 |
+53:29:18.9 |
HIP 30610 |
15.73 |
| 2026-07-31 00:00 |
06:25:47.31 |
+53:29:27.8 |
HIP 30610 |
15.50 |
| 2026-07-31 12:00 |
06:25:51.66 |
+53:29:36.9 |
HIP 30610 |
15.29 |
| 2026-08-01 00:00 |
06:25:56.00 |
+53:29:46.2 |
HIP 30610 |
15.10 |
| 2026-08-01 12:00 |
06:26:00.31 |
+53:29:55.6 |
HIP 30610 |
14.94 |
| 2026-08-02 00:00 |
06:26:04.59 |
+53:30:05.2 |
HIP 30610 |
14.80 |
| 2026-08-02 12:00 |
06:26:08.86 |
+53:30:15.0 |
HIP 30610 |
14.69 |
| 2026-08-03 00:00 |
06:26:13.10 |
+53:30:24.9 |
HIP 30610 |
14.60 |
| 2026-08-03 12:00 |
06:26:17.32 |
+53:30:35.0 |
HIP 30610 |
14.54 |
| 2026-08-04 00:00 |
06:26:21.52 |
+53:30:45.2 |
HIP 30610 |
14.50 |
| 2026-08-04 12:00 |
06:26:25.69 |
+53:30:55.6 |
HIP 30610 |
14.49 |
| 2026-08-05 00:00 |
06:26:29.83 |
+53:31:06.2 |
HIP 30610 |
14.50 |
| 2026-08-05 12:00 |
06:26:33.96 |
+53:31:16.9 |
HIP 30610 |
14.54 |
| 2026-08-06 00:00 |
06:26:38.06 |
+53:31:27.8 |
HIP 30610 |
14.60 |
| 2026-08-06 12:00 |
06:26:42.13 |
+53:31:38.9 |
HIP 30610 |
14.68 |
| 2026-08-07 00:00 |
06:26:46.18 |
+53:31:50.1 |
HIP 30610 |
14.79 |
| 2026-08-07 12:00 |
06:26:50.20 |
+53:32:01.5 |
HIP 30610 |
14.91 |
| 2026-08-08 00:00 |
06:26:54.20 |
+53:32:13.0 |
HIP 30610 |
15.06 |
| 2026-08-08 12:00 |
06:26:58.17 |
+53:32:24.7 |
HIP 30610 |
15.23 |
| 2026-08-09 00:00 |
06:27:02.11 |
+53:32:36.5 |
HIP 30610 |
15.42 |
| 2026-08-09 12:00 |
06:27:06.03 |
+53:32:48.5 |
HIP 30610 |
15.62 |
| 2026-08-10 00:00 |
06:27:09.92 |
+53:33:00.6 |
HIP 30610 |
15.84 |
| 2026-08-10 12:00 |
06:27:13.78 |
+53:33:12.9 |
HIP 30610 |
16.08 |
| 2026-08-11 00:00 |
06:27:17.62 |
+53:33:25.4 |
HIP 30610 |
16.33 |
| 2026-08-11 12:00 |
06:27:21.42 |
+53:33:38.0 |
HIP 30610 |
16.59 |
| 2026-08-12 00:00 |
06:27:25.20 |
+53:33:50.8 |
HIP 30610 |
16.87 |
| 2026-08-12 12:00 |
06:27:28.95 |
+53:34:03.7 |
HIP 30610 |
17.16 |
| 2026-08-13 00:00 |
06:27:32.67 |
+53:34:16.7 |
HIP 30610 |
17.45 |
| 2026-08-13 12:00 |
06:27:36.37 |
+53:34:30.0 |
HIP 30610 |
17.76 |
| 2026-08-14 00:00 |
06:27:40.03 |
+53:34:43.3 |
HIP 30610 |
18.08 |
| 2026-08-14 12:00 |
06:27:43.66 |
+53:34:56.8 |
HIP 30610 |
18.40 |
| 2026-08-15 00:00 |
06:27:47.26 |
+53:35:10.5 |
HIP 30610 |
18.74 |
| 2026-08-15 12:00 |
06:27:50.84 |
+53:35:24.3 |
HIP 30610 |
19.08 |
| 2026-08-16 00:00 |
06:27:54.38 |
+53:35:38.2 |
HIP 30610 |
19.42 |
| 2026-08-16 12:00 |
06:27:57.89 |
+53:35:52.3 |
HIP 30610 |
19.77 |
| 2026-08-17 00:00 |
06:28:01.37 |
+53:36:06.6 |
HIP 30610 |
20.13 |
| 2026-08-17 12:00 |
06:28:04.82 |
+53:36:21.0 |
HIP 30610 |
20.49 |
| 2026-08-18 00:00 |
06:28:08.24 |
+53:36:35.5 |
HIP 30610 |
20.85 |
| 2026-08-18 12:00 |
06:28:11.62 |
+53:36:50.2 |
HIP 30610 |
21.22 |
| 2026-08-19 00:00 |
06:28:14.97 |
+53:37:05.0 |
HIP 30610 |
21.59 |