メタデータ
| 項目 |
値 |
| Designation |
C/2012 Y3 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2012-08-25T20:18:44.000640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:30Z |
| Obs used |
150 |
| NEO |
- |
| M1 |
12.900 |
| 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) |
2013-02-01.0000000 |
| e |
0.93994217 |
| q (au) |
1.764843 |
| a (au) |
29.385733 |
| i (deg) |
73.231907 |
| Ω (om, deg) |
122.707962 |
| ω (w, deg) |
235.694296 |
| M (ma, deg) |
0.984727 |
等級
散乱 + 全体線形
$$
M_a = (11.507 + 5.732\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
11.507 |
| n |
5.732 |
| gf |
0.994 |
| gb |
-1.000 |
| k |
0.800 |
| 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 |
09:48:09.52 |
+48:40:28.5 |
HIP 48074 |
22.49 |
| 2026-03-26 12:00 |
09:48:04.85 |
+48:40:20.8 |
HIP 48074 |
22.59 |
| 2026-03-27 00:00 |
09:48:00.21 |
+48:40:12.7 |
HIP 48074 |
22.72 |
| 2026-03-27 12:00 |
09:47:55.62 |
+48:40:04.3 |
HIP 48074 |
22.89 |
| 2026-03-28 00:00 |
09:47:51.06 |
+48:39:55.5 |
HIP 48074 |
23.08 |
| 2026-03-28 12:00 |
09:47:46.55 |
+48:39:46.4 |
HIP 48074 |
23.30 |
| 2026-03-29 00:00 |
09:47:42.08 |
+48:39:36.9 |
HIP 48074 |
23.56 |
| 2026-03-29 12:00 |
09:47:37.65 |
+48:39:27.0 |
HIP 48074 |
23.83 |
| 2026-03-30 00:00 |
09:47:33.26 |
+48:39:16.7 |
HIP 48074 |
24.13 |
| 2026-03-30 12:00 |
09:47:28.91 |
+48:39:06.1 |
HIP 48074 |
24.46 |
| 2026-03-31 00:00 |
09:47:24.61 |
+48:38:55.2 |
HIP 48074 |
24.81 |
| 2026-03-31 12:00 |
09:47:20.34 |
+48:38:43.9 |
HIP 48074 |
25.17 |
| 2026-04-01 00:00 |
09:47:16.13 |
+48:38:32.2 |
HIP 48074 |
25.56 |
| 2026-04-01 12:00 |
09:47:11.95 |
+48:38:20.2 |
HIP 48074 |
25.96 |
| 2026-04-02 00:00 |
09:47:07.82 |
+48:38:07.9 |
HIP 48074 |
26.38 |
| 2026-04-02 12:00 |
09:47:03.73 |
+48:37:55.2 |
HIP 48074 |
26.81 |
| 2026-04-03 00:00 |
09:46:59.69 |
+48:37:42.1 |
HIP 48074 |
27.26 |
| 2026-04-03 12:00 |
09:46:55.69 |
+48:37:28.7 |
HIP 48074 |
27.72 |
| 2026-04-04 00:00 |
09:46:51.73 |
+48:37:15.0 |
HIP 48074 |
28.20 |
| 2026-04-04 12:00 |
09:46:47.83 |
+48:37:00.9 |
HIP 48074 |
28.68 |
| 2026-04-05 00:00 |
09:46:43.96 |
+48:36:46.5 |
HIP 48074 |
29.17 |
| 2026-04-05 12:00 |
09:46:40.14 |
+48:36:31.8 |
HIP 48074 |
29.67 |
| 2026-04-06 00:00 |
09:46:36.37 |
+48:36:16.7 |
HIP 48074 |
30.19 |
| 2026-04-06 12:00 |
09:46:32.65 |
+48:36:01.3 |
HIP 48074 |
30.70 |
| 2026-04-07 00:00 |
09:46:28.97 |
+48:35:45.6 |
HIP 48074 |
31.23 |
| 2026-04-07 12:00 |
09:46:25.33 |
+48:35:29.5 |
HIP 48074 |
31.76 |
| 2026-04-08 00:00 |
09:46:21.75 |
+48:35:13.1 |
HIP 48074 |
32.29 |
| 2026-04-08 12:00 |
09:46:18.21 |
+48:34:56.4 |
HIP 48074 |
32.83 |
| 2026-04-09 00:00 |
09:46:14.72 |
+48:34:39.4 |
HIP 48074 |
33.38 |
| 2026-04-09 12:00 |
09:46:11.27 |
+48:34:22.0 |
HIP 48074 |
33.93 |
| 2026-04-10 00:00 |
09:46:07.88 |
+48:34:04.4 |
HIP 48013 |
33.93 |
| 2026-04-10 12:00 |
09:46:04.53 |
+48:33:46.4 |
HIP 48013 |
33.84 |
| 2026-04-11 00:00 |
09:46:01.23 |
+48:33:28.1 |
HIP 47633 |
33.69 |
| 2026-04-11 12:00 |
09:45:57.98 |
+48:33:09.5 |
HIP 47633 |
33.10 |
| 2026-04-12 00:00 |
09:45:54.78 |
+48:32:50.6 |
HIP 47633 |
32.51 |
| 2026-04-12 12:00 |
09:45:51.62 |
+48:32:31.3 |
HIP 47633 |
31.94 |
| 2026-04-13 00:00 |
09:45:48.52 |
+48:32:11.8 |
HIP 47633 |
31.37 |
| 2026-04-13 12:00 |
09:45:45.47 |
+48:31:52.0 |
HIP 47633 |
30.81 |
| 2026-04-14 00:00 |
09:45:42.46 |
+48:31:31.9 |
HIP 47633 |
30.26 |
| 2026-04-14 12:00 |
09:45:39.51 |
+48:31:11.5 |
HIP 47633 |
29.72 |
| 2026-04-15 00:00 |
09:45:36.61 |
+48:30:50.7 |
HIP 47633 |
29.18 |
| 2026-04-15 12:00 |
09:45:33.75 |
+48:30:29.7 |
HIP 47633 |
28.66 |
| 2026-04-16 00:00 |
09:45:30.95 |
+48:30:08.4 |
HIP 47633 |
28.15 |