メタデータ
| 項目 |
値 |
| Designation |
C/2012 E2 (SWAN) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2012-03-15T00:41:51.241920Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:04Z |
| Obs used |
43 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2012-03-13.0000000 |
| e |
1.00049131 |
| q (au) |
0.006962 |
| a (au) |
-14.169573 |
| i (deg) |
144.430741 |
| Ω (om, deg) |
6.576461 |
| ω (w, deg) |
82.412294 |
| M (ma, deg) |
-0.037494 |
等級
散乱 + 全体線形
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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) |
| 2026-09-20 00:00 |
07:07:46.03 |
-12:22:17.5 |
HIP 34344 |
8.74 |
| 2026-09-20 12:00 |
07:07:46.89 |
-12:22:42.3 |
HIP 34344 |
8.99 |
| 2026-09-21 00:00 |
07:07:47.73 |
-12:23:07.2 |
HIP 34344 |
9.24 |
| 2026-09-21 12:00 |
07:07:48.54 |
-12:23:32.1 |
HIP 34344 |
9.51 |
| 2026-09-22 00:00 |
07:07:49.33 |
-12:23:57.0 |
HIP 34344 |
9.78 |
| 2026-09-22 12:00 |
07:07:50.09 |
-12:24:21.9 |
HIP 34344 |
10.06 |
| 2026-09-23 00:00 |
07:07:50.84 |
-12:24:46.9 |
HIP 34344 |
10.35 |
| 2026-09-23 12:00 |
07:07:51.55 |
-12:25:11.9 |
HIP 34344 |
10.65 |
| 2026-09-24 00:00 |
07:07:52.25 |
-12:25:36.9 |
HIP 34344 |
10.95 |
| 2026-09-24 12:00 |
07:07:52.92 |
-12:26:02.0 |
HIP 34344 |
11.25 |
| 2026-09-25 00:00 |
07:07:53.56 |
-12:26:27.1 |
HIP 34344 |
11.56 |
| 2026-09-25 12:00 |
07:07:54.18 |
-12:26:52.2 |
HIP 34344 |
11.88 |
| 2026-09-26 00:00 |
07:07:54.78 |
-12:27:17.3 |
HIP 34344 |
12.19 |
| 2026-09-26 12:00 |
07:07:55.35 |
-12:27:42.4 |
HIP 34344 |
12.51 |
| 2026-09-27 00:00 |
07:07:55.90 |
-12:28:07.6 |
HIP 34344 |
12.83 |
| 2026-09-27 12:00 |
07:07:56.43 |
-12:28:32.7 |
HIP 34344 |
13.15 |
| 2026-09-28 00:00 |
07:07:56.93 |
-12:28:57.9 |
HIP 34344 |
13.48 |
| 2026-09-28 12:00 |
07:07:57.40 |
-12:29:23.1 |
HIP 34344 |
13.80 |
| 2026-09-29 00:00 |
07:07:57.85 |
-12:29:48.3 |
HIP 34344 |
14.13 |
| 2026-09-29 12:00 |
07:07:58.28 |
-12:30:13.5 |
HIP 34344 |
14.46 |
| 2026-09-30 00:00 |
07:07:58.68 |
-12:30:38.8 |
HIP 34344 |
14.79 |
| 2026-09-30 12:00 |
07:07:59.06 |
-12:31:04.0 |
HIP 34344 |
15.12 |
| 2026-10-01 00:00 |
07:07:59.41 |
-12:31:29.2 |
HIP 34344 |
15.45 |
| 2026-10-01 12:00 |
07:07:59.74 |
-12:31:54.4 |
HIP 34344 |
15.78 |
| 2026-10-02 00:00 |
07:08:00.04 |
-12:32:19.7 |
HIP 34344 |
16.10 |
| 2026-10-02 12:00 |
07:08:00.32 |
-12:32:44.9 |
HIP 34344 |
16.43 |
| 2026-10-03 00:00 |
07:08:00.57 |
-12:33:10.1 |
HIP 34344 |
16.76 |
| 2026-10-03 12:00 |
07:08:00.80 |
-12:33:35.3 |
HIP 34344 |
17.09 |
| 2026-10-04 00:00 |
07:08:01.00 |
-12:34:00.5 |
HIP 34344 |
17.42 |
| 2026-10-04 12:00 |
07:08:01.18 |
-12:34:25.7 |
HIP 34344 |
17.75 |
| 2026-10-05 00:00 |
07:08:01.33 |
-12:34:50.9 |
HIP 34344 |
18.08 |
| 2026-10-05 12:00 |
07:08:01.46 |
-12:35:16.1 |
HIP 34344 |
18.40 |
| 2026-10-06 00:00 |
07:08:01.56 |
-12:35:41.3 |
HIP 34344 |
18.73 |
| 2026-10-06 12:00 |
07:08:01.63 |
-12:36:06.4 |
HIP 34454 |
18.61 |
| 2026-10-07 00:00 |
07:08:01.68 |
-12:36:31.5 |
HIP 34454 |
18.22 |
| 2026-10-07 12:00 |
07:08:01.71 |
-12:36:56.6 |
HIP 34454 |
17.84 |
| 2026-10-08 00:00 |
07:08:01.71 |
-12:37:21.7 |
HIP 34454 |
17.46 |
| 2026-10-08 12:00 |
07:08:01.68 |
-12:37:46.8 |
HIP 34454 |
17.09 |
| 2026-10-09 00:00 |
07:08:01.63 |
-12:38:11.8 |
HIP 34454 |
16.72 |
| 2026-10-09 12:00 |
07:08:01.55 |
-12:38:36.8 |
HIP 34454 |
16.35 |
| 2026-10-10 00:00 |
07:08:01.45 |
-12:39:01.8 |
HIP 34454 |
16.00 |
| 2026-10-10 12:00 |
07:08:01.32 |
-12:39:26.7 |
HIP 34454 |
15.65 |
| 2026-10-11 00:00 |
07:08:01.17 |
-12:39:51.6 |
HIP 34454 |
15.30 |