メタデータ
| 項目 |
値 |
| Designation |
C/2017 U2 (Fuls) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-08-28T02:57:59.221440Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:37Z |
| Obs used |
59 |
| NEO |
- |
| M1 |
7.300 |
| K1 |
12.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2017-12-10.0000000 |
| e |
1.00001237 |
| q (au) |
6.700825 |
| a (au) |
-541554.498455 |
| i (deg) |
95.434086 |
| Ω (om, deg) |
149.710839 |
| ω (w, deg) |
147.727081 |
| M (ma, deg) |
0.000000 |
等級
散乱 + 全体線形
$$
M_a = (3.858 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
3.858 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-1.000 |
| 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) |
| 2026-05-12 00:00 |
03:16:36.14 |
-72:00:52.7 |
HIP 15237 |
13.01 |
| 2026-05-12 12:00 |
03:16:58.91 |
-72:00:54.9 |
HIP 15237 |
13.15 |
| 2026-05-13 00:00 |
03:17:21.68 |
-72:00:57.7 |
HIP 15529 |
12.81 |
| 2026-05-13 12:00 |
03:17:44.46 |
-72:01:01.2 |
HIP 15529 |
11.09 |
| 2026-05-14 00:00 |
03:18:07.24 |
-72:01:05.3 |
HIP 15529 |
9.39 |
| 2026-05-14 12:00 |
03:18:30.02 |
-72:01:10.0 |
HIP 15529 |
7.72 |
| 2026-05-15 00:00 |
03:18:52.80 |
-72:01:15.3 |
HIP 15529 |
6.10 |
| 2026-05-15 12:00 |
03:19:15.57 |
-72:01:21.2 |
HIP 15529 |
4.59 |
| 2026-05-16 00:00 |
03:19:38.35 |
-72:01:27.7 |
HIP 15529 |
3.35 |
| 2026-05-16 12:00 |
03:20:01.13 |
-72:01:34.8 |
HIP 15529 |
2.77 |
| 2026-05-17 00:00 |
03:20:23.90 |
-72:01:42.6 |
HIP 15529 |
3.22 |
| 2026-05-17 12:00 |
03:20:46.67 |
-72:01:51.0 |
HIP 15529 |
4.40 |
| 2026-05-18 00:00 |
03:21:09.43 |
-72:02:00.0 |
HIP 15529 |
5.89 |
| 2026-05-18 12:00 |
03:21:32.19 |
-72:02:09.5 |
HIP 15529 |
7.50 |
| 2026-05-19 00:00 |
03:21:54.94 |
-72:02:19.7 |
HIP 15529 |
9.17 |
| 2026-05-19 12:00 |
03:22:17.68 |
-72:02:30.6 |
HIP 15529 |
10.87 |
| 2026-05-20 00:00 |
03:22:40.42 |
-72:02:42.0 |
HIP 15529 |
12.59 |
| 2026-05-20 12:00 |
03:23:03.15 |
-72:02:54.0 |
HIP 15529 |
14.33 |
| 2026-05-21 00:00 |
03:23:25.86 |
-72:03:06.7 |
HIP 15529 |
16.07 |
| 2026-05-21 12:00 |
03:23:48.57 |
-72:03:19.9 |
HIP 15529 |
17.82 |
| 2026-05-22 00:00 |
03:24:11.27 |
-72:03:33.8 |
HIP 15529 |
19.57 |
| 2026-05-22 12:00 |
03:24:33.95 |
-72:03:48.2 |
HIP 15529 |
21.32 |
| 2026-05-23 00:00 |
03:24:56.62 |
-72:04:03.3 |
HIP 15529 |
23.08 |
| 2026-05-23 12:00 |
03:25:19.28 |
-72:04:18.9 |
HIP 15529 |
24.84 |
| 2026-05-24 00:00 |
03:25:41.93 |
-72:04:35.2 |
HIP 15529 |
26.60 |
| 2026-05-24 12:00 |
03:26:04.56 |
-72:04:52.1 |
HIP 15749 |
28.11 |
| 2026-05-25 00:00 |
03:26:27.17 |
-72:05:09.5 |
HIP 16392 |
27.34 |
| 2026-05-25 12:00 |
03:26:49.77 |
-72:05:27.6 |
HIP 16392 |
25.83 |
| 2026-05-26 00:00 |
03:27:12.36 |
-72:05:46.2 |
HIP 16392 |
24.34 |
| 2026-05-26 12:00 |
03:27:34.92 |
-72:06:05.5 |
HIP 16392 |
22.88 |
| 2026-05-27 00:00 |
03:27:57.47 |
-72:06:25.3 |
HIP 16392 |
21.46 |
| 2026-05-27 12:00 |
03:28:20.00 |
-72:06:45.7 |
HIP 16392 |
20.09 |
| 2026-05-28 00:00 |
03:28:42.51 |
-72:07:06.8 |
HIP 16392 |
18.77 |
| 2026-05-28 12:00 |
03:29:05.00 |
-72:07:28.4 |
HIP 16392 |
17.52 |
| 2026-05-29 00:00 |
03:29:27.47 |
-72:07:50.6 |
HIP 16392 |
16.36 |
| 2026-05-29 12:00 |
03:29:49.92 |
-72:08:13.3 |
HIP 16392 |
15.30 |
| 2026-05-30 00:00 |
03:30:12.34 |
-72:08:36.7 |
HIP 16392 |
14.37 |
| 2026-05-30 12:00 |
03:30:34.75 |
-72:09:00.7 |
HIP 16392 |
13.59 |
| 2026-05-31 00:00 |
03:30:57.13 |
-72:09:25.2 |
HIP 16392 |
12.99 |
| 2026-05-31 12:00 |
03:31:19.49 |
-72:09:50.3 |
HIP 16392 |
12.61 |
| 2026-06-01 00:00 |
03:31:41.82 |
-72:10:16.0 |
HIP 16392 |
12.44 |
| 2026-06-01 12:00 |
03:32:04.13 |
-72:10:42.3 |
HIP 16392 |
12.52 |
| 2026-06-02 00:00 |
03:32:26.41 |
-72:11:09.2 |
HIP 16392 |
12.83 |