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 |
1.000 |
| gb |
-0.502 |
| 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 |
04:08:38.53 |
-73:57:55.3 |
HIP 19671 |
21.61 |
| 2026-07-29 12:00 |
04:08:52.44 |
-73:59:14.9 |
HIP 19671 |
21.65 |
| 2026-07-30 00:00 |
04:09:06.21 |
-74:00:34.7 |
HIP 19671 |
21.83 |
| 2026-07-30 12:00 |
04:09:19.87 |
-74:01:54.9 |
HIP 19671 |
22.14 |
| 2026-07-31 00:00 |
04:09:33.40 |
-74:03:15.2 |
HIP 19671 |
22.57 |
| 2026-07-31 12:00 |
04:09:46.79 |
-74:04:35.9 |
HIP 19671 |
23.13 |
| 2026-08-01 00:00 |
04:10:00.06 |
-74:05:56.8 |
HIP 19671 |
23.79 |
| 2026-08-01 12:00 |
04:10:13.20 |
-74:07:17.9 |
HIP 19671 |
24.55 |
| 2026-08-02 00:00 |
04:10:26.21 |
-74:08:39.3 |
HIP 19671 |
25.40 |
| 2026-08-02 12:00 |
04:10:39.09 |
-74:10:01.0 |
HIP 19671 |
26.34 |
| 2026-08-03 00:00 |
04:10:51.84 |
-74:11:22.8 |
HIP 19671 |
27.34 |
| 2026-08-03 12:00 |
04:11:04.45 |
-74:12:45.0 |
HIP 19671 |
28.41 |
| 2026-08-04 00:00 |
04:11:16.92 |
-74:14:07.3 |
HIP 19671 |
29.54 |
| 2026-08-04 12:00 |
04:11:29.26 |
-74:15:29.9 |
HIP 19671 |
30.72 |
| 2026-08-05 00:00 |
04:11:41.46 |
-74:16:52.7 |
HIP 19671 |
31.94 |
| 2026-08-05 12:00 |
04:11:53.53 |
-74:18:15.8 |
HIP 19671 |
33.20 |
| 2026-08-06 00:00 |
04:12:05.45 |
-74:19:39.0 |
HIP 19671 |
34.49 |
| 2026-08-06 12:00 |
04:12:17.24 |
-74:21:02.5 |
HIP 19671 |
35.81 |
| 2026-08-07 00:00 |
04:12:28.88 |
-74:22:26.1 |
HIP 19671 |
37.16 |
| 2026-08-07 12:00 |
04:12:40.38 |
-74:23:50.0 |
HIP 19671 |
38.54 |
| 2026-08-08 00:00 |
04:12:51.73 |
-74:25:14.1 |
HIP 19671 |
39.93 |
| 2026-08-08 12:00 |
04:13:02.94 |
-74:26:38.4 |
HIP 19671 |
41.35 |
| 2026-08-09 00:00 |
04:13:14.00 |
-74:28:02.8 |
HIP 19671 |
42.77 |
| 2026-08-09 12:00 |
04:13:24.92 |
-74:29:27.5 |
HIP 19671 |
44.22 |
| 2026-08-10 00:00 |
04:13:35.69 |
-74:30:52.3 |
HIP 20592 |
44.25 |
| 2026-08-10 12:00 |
04:13:46.30 |
-74:32:17.3 |
HIP 20592 |
43.54 |
| 2026-08-11 00:00 |
04:13:56.77 |
-74:33:42.5 |
HIP 20592 |
42.90 |
| 2026-08-11 12:00 |
04:14:07.08 |
-74:35:07.8 |
HIP 20592 |
42.31 |
| 2026-08-12 00:00 |
04:14:17.24 |
-74:36:33.3 |
HIP 20592 |
41.79 |
| 2026-08-12 12:00 |
04:14:27.25 |
-74:37:58.9 |
HIP 20592 |
41.33 |
| 2026-08-13 00:00 |
04:14:37.10 |
-74:39:24.7 |
HIP 20592 |
40.94 |
| 2026-08-13 12:00 |
04:14:46.79 |
-74:40:50.6 |
HIP 19909 |
40.21 |
| 2026-08-14 00:00 |
04:14:56.33 |
-74:42:16.7 |
HIP 19909 |
38.71 |
| 2026-08-14 12:00 |
04:15:05.70 |
-74:43:42.9 |
HIP 19909 |
37.21 |
| 2026-08-15 00:00 |
04:15:14.92 |
-74:45:09.2 |
HIP 19909 |
35.71 |
| 2026-08-15 12:00 |
04:15:23.98 |
-74:46:35.6 |
HIP 19909 |
34.22 |
| 2026-08-16 00:00 |
04:15:32.87 |
-74:48:02.2 |
HIP 19909 |
32.73 |
| 2026-08-16 12:00 |
04:15:41.60 |
-74:49:28.9 |
HIP 19909 |
31.25 |
| 2026-08-17 00:00 |
04:15:50.17 |
-74:50:55.6 |
HIP 19909 |
29.77 |
| 2026-08-17 12:00 |
04:15:58.57 |
-74:52:22.5 |
HIP 19909 |
28.30 |
| 2026-08-18 00:00 |
04:16:06.81 |
-74:53:49.4 |
HIP 19909 |
26.84 |
| 2026-08-18 12:00 |
04:16:14.88 |
-74:55:16.5 |
HIP 19909 |
25.38 |
| 2026-08-19 00:00 |
04:16:22.78 |
-74:56:43.6 |
HIP 19909 |
23.94 |