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) |
| 2026-03-26 00:00 |
17:33:26.50 |
+58:42:27.9 |
HIP 85709 |
29.27 |
| 2026-03-26 12:00 |
17:33:24.93 |
+58:43:30.9 |
HIP 85709 |
29.90 |
| 2026-03-27 00:00 |
17:33:23.30 |
+58:44:33.7 |
HIP 85709 |
30.55 |
| 2026-03-27 12:00 |
17:33:21.60 |
+58:45:36.4 |
HIP 85709 |
31.22 |
| 2026-03-28 00:00 |
17:33:19.84 |
+58:46:39.0 |
HIP 85709 |
31.90 |
| 2026-03-28 12:00 |
17:33:18.01 |
+58:47:41.5 |
HIP 85709 |
32.59 |
| 2026-03-29 00:00 |
17:33:16.11 |
+58:48:43.8 |
HIP 85709 |
33.30 |
| 2026-03-29 12:00 |
17:33:14.14 |
+58:49:46.0 |
HIP 85709 |
34.02 |
| 2026-03-30 00:00 |
17:33:12.11 |
+58:50:48.1 |
HIP 85709 |
34.75 |
| 2026-03-30 12:00 |
17:33:10.02 |
+58:51:50.0 |
HIP 85709 |
35.49 |
| 2026-03-31 00:00 |
17:33:07.85 |
+58:52:51.8 |
HIP 85522 |
35.82 |
| 2026-03-31 12:00 |
17:33:05.63 |
+58:53:53.5 |
HIP 85522 |
35.28 |
| 2026-04-01 00:00 |
17:33:03.33 |
+58:54:55.0 |
HIP 85522 |
34.76 |
| 2026-04-01 12:00 |
17:33:00.97 |
+58:55:56.3 |
HIP 85522 |
34.26 |
| 2026-04-02 00:00 |
17:32:58.55 |
+58:56:57.5 |
HIP 85522 |
33.77 |
| 2026-04-02 12:00 |
17:32:56.05 |
+58:57:58.5 |
HIP 85522 |
33.30 |
| 2026-04-03 00:00 |
17:32:53.50 |
+58:58:59.4 |
HIP 85522 |
32.86 |
| 2026-04-03 12:00 |
17:32:50.88 |
+59:00:00.1 |
HIP 85522 |
32.43 |
| 2026-04-04 00:00 |
17:32:48.19 |
+59:01:00.6 |
HIP 85522 |
32.03 |
| 2026-04-04 12:00 |
17:32:45.44 |
+59:02:00.9 |
HIP 85522 |
31.65 |
| 2026-04-05 00:00 |
17:32:42.62 |
+59:03:01.0 |
HIP 85522 |
31.29 |
| 2026-04-05 12:00 |
17:32:39.74 |
+59:04:01.0 |
HIP 85522 |
30.96 |
| 2026-04-06 00:00 |
17:32:36.79 |
+59:05:00.8 |
HIP 85522 |
30.65 |
| 2026-04-06 12:00 |
17:32:33.78 |
+59:06:00.3 |
HIP 85522 |
30.37 |
| 2026-04-07 00:00 |
17:32:30.71 |
+59:06:59.7 |
HIP 85522 |
30.11 |
| 2026-04-07 12:00 |
17:32:27.57 |
+59:07:58.8 |
HIP 85522 |
29.88 |
| 2026-04-08 00:00 |
17:32:24.36 |
+59:08:57.8 |
HIP 85522 |
29.69 |
| 2026-04-08 12:00 |
17:32:21.09 |
+59:09:56.5 |
HIP 85522 |
29.52 |
| 2026-04-09 00:00 |
17:32:17.76 |
+59:10:55.0 |
HIP 85522 |
29.37 |
| 2026-04-09 12:00 |
17:32:14.37 |
+59:11:53.3 |
HIP 85522 |
29.26 |
| 2026-04-10 00:00 |
17:32:10.91 |
+59:12:51.4 |
HIP 85522 |
29.18 |
| 2026-04-10 12:00 |
17:32:07.39 |
+59:13:49.2 |
HIP 85522 |
29.13 |
| 2026-04-11 00:00 |
17:32:03.80 |
+59:14:46.8 |
HIP 85522 |
29.11 |
| 2026-04-11 12:00 |
17:32:00.15 |
+59:15:44.2 |
HIP 85522 |
29.12 |
| 2026-04-12 00:00 |
17:31:56.44 |
+59:16:41.3 |
HIP 85634 |
28.62 |
| 2026-04-12 12:00 |
17:31:52.67 |
+59:17:38.2 |
HIP 85634 |
27.56 |
| 2026-04-13 00:00 |
17:31:48.83 |
+59:18:34.8 |
HIP 85634 |
26.50 |
| 2026-04-13 12:00 |
17:31:44.93 |
+59:19:31.1 |
HIP 85634 |
25.44 |
| 2026-04-14 00:00 |
17:31:40.97 |
+59:20:27.2 |
HIP 85634 |
24.38 |
| 2026-04-14 12:00 |
17:31:36.95 |
+59:21:23.1 |
HIP 85634 |
23.31 |
| 2026-04-15 00:00 |
17:31:32.87 |
+59:22:18.6 |
HIP 85634 |
22.25 |
| 2026-04-15 12:00 |
17:31:28.72 |
+59:23:13.9 |
HIP 85634 |
21.19 |
| 2026-04-16 00:00 |
17:31:24.52 |
+59:24:08.9 |
HIP 85634 |
20.13 |