メタデータ
| 項目 |
値 |
| Designation |
C/2013 G7 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2014-03-18T16:01:39.025920Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:34Z |
| Obs used |
305 |
| NEO |
- |
| M1 |
6.000 |
| K1 |
12.250 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2013-07-23.0000000 |
| e |
0.99786135 |
| q (au) |
4.677407 |
| a (au) |
2187.083310 |
| i (deg) |
105.110084 |
| Ω (om, deg) |
48.402717 |
| ω (w, deg) |
218.263829 |
| M (ma, deg) |
359.997700 |
等級
散乱 + 全体線形
$$
M_a = (8.939 + 3.225\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
8.939 |
| n |
3.225 |
| gf |
0.999 |
| gb |
-0.866 |
| k |
0.999 |
| δ90 |
9.999 |
| 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 |
03:36:03.76 |
+07:57:08.2 |
HIP 16609 |
39.58 |
| 2026-07-29 12:00 |
03:36:04.95 |
+07:57:07.9 |
HIP 16609 |
39.84 |
| 2026-07-30 00:00 |
03:36:06.11 |
+07:57:07.4 |
HIP 16609 |
40.09 |
| 2026-07-30 12:00 |
03:36:07.23 |
+07:57:06.7 |
HIP 16609 |
40.33 |
| 2026-07-31 00:00 |
03:36:08.32 |
+07:57:05.8 |
HIP 16609 |
40.57 |
| 2026-07-31 12:00 |
03:36:09.38 |
+07:57:04.8 |
HIP 16609 |
40.81 |
| 2026-08-01 00:00 |
03:36:10.40 |
+07:57:03.7 |
HIP 16609 |
41.04 |
| 2026-08-01 12:00 |
03:36:11.38 |
+07:57:02.4 |
HIP 16609 |
41.26 |
| 2026-08-02 00:00 |
03:36:12.34 |
+07:57:00.9 |
HIP 16609 |
41.48 |
| 2026-08-02 12:00 |
03:36:13.25 |
+07:56:59.3 |
HIP 16609 |
41.69 |
| 2026-08-03 00:00 |
03:36:14.14 |
+07:56:57.5 |
HIP 16609 |
41.89 |
| 2026-08-03 12:00 |
03:36:14.99 |
+07:56:55.6 |
HIP 16609 |
42.09 |
| 2026-08-04 00:00 |
03:36:15.80 |
+07:56:53.5 |
HIP 16609 |
42.29 |
| 2026-08-04 12:00 |
03:36:16.58 |
+07:56:51.2 |
HIP 16609 |
42.47 |
| 2026-08-05 00:00 |
03:36:17.32 |
+07:56:48.8 |
HIP 16609 |
42.65 |
| 2026-08-05 12:00 |
03:36:18.03 |
+07:56:46.3 |
HIP 16609 |
42.83 |
| 2026-08-06 00:00 |
03:36:18.70 |
+07:56:43.6 |
HIP 16609 |
42.99 |
| 2026-08-06 12:00 |
03:36:19.34 |
+07:56:40.7 |
HIP 16609 |
43.16 |
| 2026-08-07 00:00 |
03:36:19.94 |
+07:56:37.7 |
HIP 16609 |
43.31 |
| 2026-08-07 12:00 |
03:36:20.51 |
+07:56:34.6 |
HIP 16609 |
43.46 |
| 2026-08-08 00:00 |
03:36:21.04 |
+07:56:31.2 |
HIP 16609 |
43.60 |
| 2026-08-08 12:00 |
03:36:21.53 |
+07:56:27.8 |
HIP 16609 |
43.74 |
| 2026-08-09 00:00 |
03:36:21.99 |
+07:56:24.2 |
HIP 16609 |
43.86 |
| 2026-08-09 12:00 |
03:36:22.41 |
+07:56:20.4 |
HIP 16609 |
43.99 |
| 2026-08-10 00:00 |
03:36:22.80 |
+07:56:16.5 |
HIP 16609 |
44.10 |
| 2026-08-10 12:00 |
03:36:23.15 |
+07:56:12.4 |
HIP 16609 |
44.21 |
| 2026-08-11 00:00 |
03:36:23.46 |
+07:56:08.2 |
HIP 16609 |
44.31 |
| 2026-08-11 12:00 |
03:36:23.73 |
+07:56:03.9 |
HIP 16609 |
44.41 |
| 2026-08-12 00:00 |
03:36:23.97 |
+07:55:59.4 |
HIP 16918 |
44.45 |
| 2026-08-12 12:00 |
03:36:24.17 |
+07:55:54.7 |
HIP 16918 |
44.35 |
| 2026-08-13 00:00 |
03:36:24.34 |
+07:55:49.9 |
HIP 16918 |
44.27 |
| 2026-08-13 12:00 |
03:36:24.47 |
+07:55:45.0 |
HIP 16918 |
44.18 |
| 2026-08-14 00:00 |
03:36:24.56 |
+07:55:39.9 |
HIP 16918 |
44.09 |
| 2026-08-14 12:00 |
03:36:24.61 |
+07:55:34.7 |
HIP 16918 |
44.01 |
| 2026-08-15 00:00 |
03:36:24.63 |
+07:55:29.3 |
HIP 16918 |
43.93 |
| 2026-08-15 12:00 |
03:36:24.61 |
+07:55:23.8 |
HIP 16918 |
43.85 |
| 2026-08-16 00:00 |
03:36:24.55 |
+07:55:18.1 |
HIP 16918 |
43.77 |
| 2026-08-16 12:00 |
03:36:24.45 |
+07:55:12.3 |
HIP 16918 |
43.69 |
| 2026-08-17 00:00 |
03:36:24.32 |
+07:55:06.4 |
HIP 16918 |
43.62 |
| 2026-08-17 12:00 |
03:36:24.15 |
+07:55:00.3 |
HIP 16918 |
43.55 |
| 2026-08-18 00:00 |
03:36:23.95 |
+07:54:54.1 |
HIP 16918 |
43.48 |
| 2026-08-18 12:00 |
03:36:23.70 |
+07:54:47.8 |
HIP 16918 |
43.42 |
| 2026-08-19 00:00 |
03:36:23.42 |
+07:54:41.3 |
HIP 16918 |
43.35 |