メタデータ
| 項目 |
値 |
| Designation |
C/2017 A3 (Elenin) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-01-30T14:31:52.288320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:28Z |
| Obs used |
186 |
| NEO |
- |
| M1 |
9.700 |
| K1 |
10.000 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2017-02-10.0000000 |
| e |
0.91107616 |
| q (au) |
3.854543 |
| a (au) |
43.346563 |
| i (deg) |
98.508477 |
| Ω (om, deg) |
97.903943 |
| ω (w, deg) |
304.107532 |
| M (ma, deg) |
0.035899 |
等級
散乱 + 全体線形
$$
M_a = (5.803 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
5.803 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.998 |
| 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 |
20:00:36.11 |
+80:06:16.0 |
HIP 98666 |
25.86 |
| 2026-07-29 12:00 |
20:00:02.60 |
+80:05:55.4 |
HIP 98666 |
25.84 |
| 2026-07-30 00:00 |
19:59:29.16 |
+80:05:33.8 |
HIP 98666 |
25.90 |
| 2026-07-30 12:00 |
19:58:55.81 |
+80:05:11.4 |
HIP 98666 |
26.03 |
| 2026-07-31 00:00 |
19:58:22.54 |
+80:04:48.1 |
HIP 98666 |
26.23 |
| 2026-07-31 12:00 |
19:57:49.36 |
+80:04:23.8 |
HIP 98666 |
26.50 |
| 2026-08-01 00:00 |
19:57:16.28 |
+80:03:58.7 |
HIP 98666 |
26.84 |
| 2026-08-01 12:00 |
19:56:43.30 |
+80:03:32.6 |
HIP 98666 |
27.24 |
| 2026-08-02 00:00 |
19:56:10.42 |
+80:03:05.7 |
HIP 98666 |
27.71 |
| 2026-08-02 12:00 |
19:55:37.65 |
+80:02:37.9 |
HIP 98666 |
28.24 |
| 2026-08-03 00:00 |
19:55:04.99 |
+80:02:09.1 |
HIP 98666 |
28.83 |
| 2026-08-03 12:00 |
19:54:32.44 |
+80:01:39.5 |
HIP 98666 |
29.47 |
| 2026-08-04 00:00 |
19:54:00.02 |
+80:01:09.0 |
HIP 98666 |
30.16 |
| 2026-08-04 12:00 |
19:53:27.72 |
+80:00:37.6 |
HIP 98666 |
30.89 |
| 2026-08-05 00:00 |
19:52:55.54 |
+80:00:05.3 |
HIP 98666 |
31.68 |
| 2026-08-05 12:00 |
19:52:23.50 |
+79:59:32.2 |
HIP 98666 |
32.50 |
| 2026-08-06 00:00 |
19:51:51.59 |
+79:58:58.2 |
HIP 98666 |
33.36 |
| 2026-08-06 12:00 |
19:51:19.83 |
+79:58:23.2 |
HIP 96780 |
32.94 |
| 2026-08-07 00:00 |
19:50:48.20 |
+79:57:47.5 |
HIP 96780 |
31.44 |
| 2026-08-07 12:00 |
19:50:16.73 |
+79:57:10.8 |
HIP 96780 |
29.94 |
| 2026-08-08 00:00 |
19:49:45.40 |
+79:56:33.3 |
HIP 96780 |
28.43 |
| 2026-08-08 12:00 |
19:49:14.23 |
+79:55:54.9 |
HIP 96780 |
26.93 |
| 2026-08-09 00:00 |
19:48:43.22 |
+79:55:15.6 |
HIP 96780 |
25.43 |
| 2026-08-09 12:00 |
19:48:12.37 |
+79:54:35.5 |
HIP 96780 |
23.92 |
| 2026-08-10 00:00 |
19:47:41.69 |
+79:53:54.6 |
HIP 96780 |
22.41 |
| 2026-08-10 12:00 |
19:47:11.17 |
+79:53:12.8 |
HIP 96780 |
20.90 |
| 2026-08-11 00:00 |
19:46:40.83 |
+79:52:30.1 |
HIP 96780 |
19.39 |
| 2026-08-11 12:00 |
19:46:10.67 |
+79:51:46.7 |
HIP 96780 |
17.88 |
| 2026-08-12 00:00 |
19:45:40.69 |
+79:51:02.3 |
HIP 96780 |
16.37 |
| 2026-08-12 12:00 |
19:45:10.89 |
+79:50:17.2 |
HIP 96780 |
14.86 |
| 2026-08-13 00:00 |
19:44:41.29 |
+79:49:31.2 |
HIP 96780 |
13.34 |
| 2026-08-13 12:00 |
19:44:11.87 |
+79:48:44.4 |
HIP 96780 |
11.83 |
| 2026-08-14 00:00 |
19:43:42.65 |
+79:47:56.8 |
HIP 96780 |
10.31 |
| 2026-08-14 12:00 |
19:43:13.62 |
+79:47:08.4 |
HIP 96780 |
8.80 |
| 2026-08-15 00:00 |
19:42:44.80 |
+79:46:19.2 |
HIP 96780 |
7.29 |
| 2026-08-15 12:00 |
19:42:16.18 |
+79:45:29.1 |
HIP 96780 |
5.79 |
| 2026-08-16 00:00 |
19:41:47.76 |
+79:44:38.3 |
HIP 96780 |
4.30 |
| 2026-08-16 12:00 |
19:41:19.56 |
+79:43:46.7 |
HIP 96780 |
2.85 |
| 2026-08-17 00:00 |
19:40:51.57 |
+79:42:54.3 |
HIP 96780 |
1.54 |
| 2026-08-17 12:00 |
19:40:23.79 |
+79:42:01.2 |
HIP 96780 |
1.15 |
| 2026-08-18 00:00 |
19:39:56.23 |
+79:41:07.2 |
HIP 96780 |
2.22 |
| 2026-08-18 12:00 |
19:39:28.89 |
+79:40:12.5 |
HIP 96780 |
3.64 |
| 2026-08-19 00:00 |
19:39:01.77 |
+79:39:17.1 |
HIP 96780 |
5.12 |