メタデータ
| 項目 |
値 |
| Designation |
C/2013 G2 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2012-12-06T08:24:02.825280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:32Z |
| Obs used |
111 |
| NEO |
- |
| M1 |
13.700 |
| K1 |
4.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2013-05-24.0000000 |
| e |
1.00017667 |
| q (au) |
2.154122 |
| a (au) |
-12193.190355 |
| i (deg) |
96.001965 |
| Ω (om, deg) |
274.112530 |
| ω (w, deg) |
293.912193 |
| M (ma, deg) |
0.000123 |
等級
散乱 + 全体線形
$$
M_a = (11.810 + 2.787\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
11.810 |
| n |
2.787 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| 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 |
17:07:32.79 |
+59:55:06.9 |
HIP 83454 |
37.51 |
| 2026-07-29 12:00 |
17:07:27.56 |
+59:54:27.9 |
HIP 83454 |
36.61 |
| 2026-07-30 00:00 |
17:07:22.39 |
+59:53:48.5 |
HIP 83454 |
35.72 |
| 2026-07-30 12:00 |
17:07:17.26 |
+59:53:08.9 |
HIP 83454 |
34.83 |
| 2026-07-31 00:00 |
17:07:12.19 |
+59:52:28.9 |
HIP 83454 |
33.94 |
| 2026-07-31 12:00 |
17:07:07.17 |
+59:51:48.5 |
HIP 83454 |
33.06 |
| 2026-08-01 00:00 |
17:07:02.21 |
+59:51:07.9 |
HIP 83454 |
32.19 |
| 2026-08-01 12:00 |
17:06:57.30 |
+59:50:26.9 |
HIP 83454 |
31.32 |
| 2026-08-02 00:00 |
17:06:52.45 |
+59:49:45.7 |
HIP 83454 |
30.46 |
| 2026-08-02 12:00 |
17:06:47.65 |
+59:49:04.1 |
HIP 83454 |
29.60 |
| 2026-08-03 00:00 |
17:06:42.91 |
+59:48:22.2 |
HIP 83454 |
28.75 |
| 2026-08-03 12:00 |
17:06:38.22 |
+59:47:40.0 |
HIP 83454 |
27.91 |
| 2026-08-04 00:00 |
17:06:33.59 |
+59:46:57.5 |
HIP 83454 |
27.08 |
| 2026-08-04 12:00 |
17:06:29.01 |
+59:46:14.8 |
HIP 83454 |
26.25 |
| 2026-08-05 00:00 |
17:06:24.50 |
+59:45:31.7 |
HIP 83454 |
25.44 |
| 2026-08-05 12:00 |
17:06:20.03 |
+59:44:48.3 |
HIP 83454 |
24.64 |
| 2026-08-06 00:00 |
17:06:15.63 |
+59:44:04.7 |
HIP 83454 |
23.86 |
| 2026-08-06 12:00 |
17:06:11.28 |
+59:43:20.7 |
HIP 83454 |
23.08 |
| 2026-08-07 00:00 |
17:06:06.99 |
+59:42:36.5 |
HIP 83454 |
22.33 |
| 2026-08-07 12:00 |
17:06:02.76 |
+59:41:52.0 |
HIP 83454 |
21.59 |
| 2026-08-08 00:00 |
17:05:58.59 |
+59:41:07.3 |
HIP 83454 |
20.87 |
| 2026-08-08 12:00 |
17:05:54.48 |
+59:40:22.3 |
HIP 83454 |
20.17 |
| 2026-08-09 00:00 |
17:05:50.42 |
+59:39:37.0 |
HIP 83454 |
19.49 |
| 2026-08-09 12:00 |
17:05:46.43 |
+59:38:51.4 |
HIP 83454 |
18.84 |
| 2026-08-10 00:00 |
17:05:42.49 |
+59:38:05.6 |
HIP 83454 |
18.22 |
| 2026-08-10 12:00 |
17:05:38.61 |
+59:37:19.5 |
HIP 83454 |
17.63 |
| 2026-08-11 00:00 |
17:05:34.80 |
+59:36:33.2 |
HIP 83454 |
17.08 |
| 2026-08-11 12:00 |
17:05:31.04 |
+59:35:46.7 |
HIP 83454 |
16.57 |
| 2026-08-12 00:00 |
17:05:27.35 |
+59:34:59.9 |
HIP 83454 |
16.09 |
| 2026-08-12 12:00 |
17:05:23.71 |
+59:34:12.9 |
HIP 83454 |
15.67 |
| 2026-08-13 00:00 |
17:05:20.14 |
+59:33:25.6 |
HIP 83454 |
15.29 |
| 2026-08-13 12:00 |
17:05:16.62 |
+59:32:38.1 |
HIP 83454 |
14.97 |
| 2026-08-14 00:00 |
17:05:13.17 |
+59:31:50.4 |
HIP 83454 |
14.71 |
| 2026-08-14 12:00 |
17:05:09.78 |
+59:31:02.5 |
HIP 83454 |
14.50 |
| 2026-08-15 00:00 |
17:05:06.46 |
+59:30:14.3 |
HIP 83454 |
14.36 |
| 2026-08-15 12:00 |
17:05:03.19 |
+59:29:26.0 |
HIP 83454 |
14.28 |
| 2026-08-16 00:00 |
17:04:59.99 |
+59:28:37.4 |
HIP 83454 |
14.27 |
| 2026-08-16 12:00 |
17:04:56.85 |
+59:27:48.7 |
HIP 83454 |
14.33 |
| 2026-08-17 00:00 |
17:04:53.77 |
+59:26:59.7 |
HIP 83454 |
14.44 |
| 2026-08-17 12:00 |
17:04:50.75 |
+59:26:10.6 |
HIP 83454 |
14.63 |
| 2026-08-18 00:00 |
17:04:47.80 |
+59:25:21.2 |
HIP 83454 |
14.87 |
| 2026-08-18 12:00 |
17:04:44.91 |
+59:24:31.7 |
HIP 83454 |
15.17 |
| 2026-08-19 00:00 |
17:04:42.08 |
+59:23:42.0 |
HIP 83451 |
15.51 |