メタデータ
| 項目 |
値 |
| Designation |
C/2018 EF9 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-05-23T03:04:52.170240Z |
| Orbit solution date (soln_date, UTC) |
2023-02-13T23:12:43Z |
| Obs used |
191 |
| NEO |
- |
| M1 |
8.600 |
| K1 |
45.250 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2018-04-18.0000000 |
| e |
0.99757417 |
| q (au) |
1.556633 |
| a (au) |
641.691299 |
| i (deg) |
84.694453 |
| Ω (om, deg) |
172.578066 |
| ω (w, deg) |
72.616575 |
| M (ma, deg) |
359.997870 |
等級
散乱 + 全体線形
$$
M_a = (8.870 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
8.870 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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 |
01:13:57.02 |
-36:03:01.2 |
HIP 5757 |
8.12 |
| 2026-05-12 12:00 |
01:14:02.75 |
-36:03:17.1 |
HIP 5757 |
8.05 |
| 2026-05-13 00:00 |
01:14:08.46 |
-36:03:33.5 |
HIP 5757 |
8.14 |
| 2026-05-13 12:00 |
01:14:14.15 |
-36:03:50.5 |
HIP 5757 |
8.39 |
| 2026-05-14 00:00 |
01:14:19.80 |
-36:04:07.9 |
HIP 5757 |
8.78 |
| 2026-05-14 12:00 |
01:14:25.44 |
-36:04:25.9 |
HIP 5757 |
9.30 |
| 2026-05-15 00:00 |
01:14:31.04 |
-36:04:44.3 |
HIP 5757 |
9.92 |
| 2026-05-15 12:00 |
01:14:36.61 |
-36:05:03.3 |
HIP 5757 |
10.62 |
| 2026-05-16 00:00 |
01:14:42.16 |
-36:05:22.7 |
HIP 5757 |
11.39 |
| 2026-05-16 12:00 |
01:14:47.68 |
-36:05:42.7 |
HIP 5757 |
12.22 |
| 2026-05-17 00:00 |
01:14:53.17 |
-36:06:03.1 |
HIP 5757 |
13.08 |
| 2026-05-17 12:00 |
01:14:58.63 |
-36:06:24.1 |
HIP 5757 |
13.99 |
| 2026-05-18 00:00 |
01:15:04.07 |
-36:06:45.5 |
HIP 5757 |
14.91 |
| 2026-05-18 12:00 |
01:15:09.47 |
-36:07:07.5 |
HIP 5757 |
15.86 |
| 2026-05-19 00:00 |
01:15:14.84 |
-36:07:29.9 |
HIP 5757 |
16.83 |
| 2026-05-19 12:00 |
01:15:20.18 |
-36:07:52.8 |
HIP 5757 |
17.81 |
| 2026-05-20 00:00 |
01:15:25.50 |
-36:08:16.3 |
HIP 5757 |
18.80 |
| 2026-05-20 12:00 |
01:15:30.78 |
-36:08:40.2 |
HIP 5757 |
19.80 |
| 2026-05-21 00:00 |
01:15:36.03 |
-36:09:04.6 |
HIP 5757 |
20.81 |
| 2026-05-21 12:00 |
01:15:41.24 |
-36:09:29.5 |
HIP 5757 |
21.82 |
| 2026-05-22 00:00 |
01:15:46.43 |
-36:09:54.9 |
HIP 5757 |
22.84 |
| 2026-05-22 12:00 |
01:15:51.58 |
-36:10:20.8 |
HIP 5757 |
23.86 |
| 2026-05-23 00:00 |
01:15:56.70 |
-36:10:47.2 |
HIP 5757 |
24.88 |
| 2026-05-23 12:00 |
01:16:01.79 |
-36:11:14.1 |
HIP 5757 |
25.91 |
| 2026-05-24 00:00 |
01:16:06.84 |
-36:11:41.4 |
HIP 5757 |
26.93 |
| 2026-05-24 12:00 |
01:16:11.86 |
-36:12:09.2 |
HIP 5757 |
27.96 |
| 2026-05-25 00:00 |
01:16:16.85 |
-36:12:37.6 |
HIP 6068 |
27.16 |
| 2026-05-25 12:00 |
01:16:21.80 |
-36:13:06.3 |
HIP 6068 |
26.12 |
| 2026-05-26 00:00 |
01:16:26.72 |
-36:13:35.6 |
HIP 6068 |
25.08 |
| 2026-05-26 12:00 |
01:16:31.61 |
-36:14:05.4 |
HIP 6068 |
24.05 |
| 2026-05-27 00:00 |
01:16:36.46 |
-36:14:35.6 |
HIP 6068 |
23.02 |
| 2026-05-27 12:00 |
01:16:41.27 |
-36:15:06.3 |
HIP 6068 |
21.99 |
| 2026-05-28 00:00 |
01:16:46.05 |
-36:15:37.4 |
HIP 6068 |
20.98 |
| 2026-05-28 12:00 |
01:16:50.79 |
-36:16:09.1 |
HIP 6068 |
19.97 |
| 2026-05-29 00:00 |
01:16:55.50 |
-36:16:41.2 |
HIP 6068 |
18.96 |
| 2026-05-29 12:00 |
01:17:00.17 |
-36:17:13.8 |
HIP 6068 |
17.96 |
| 2026-05-30 00:00 |
01:17:04.80 |
-36:17:46.8 |
HIP 6068 |
16.98 |
| 2026-05-30 12:00 |
01:17:09.40 |
-36:18:20.3 |
HIP 6068 |
16.00 |
| 2026-05-31 00:00 |
01:17:13.96 |
-36:18:54.3 |
HIP 6068 |
15.03 |
| 2026-05-31 12:00 |
01:17:18.49 |
-36:19:28.8 |
HIP 6068 |
14.08 |
| 2026-06-01 00:00 |
01:17:22.97 |
-36:20:03.7 |
HIP 6068 |
13.14 |
| 2026-06-01 12:00 |
01:17:27.42 |
-36:20:39.0 |
HIP 6068 |
12.22 |
| 2026-06-02 00:00 |
01:17:31.83 |
-36:21:14.9 |
HIP 6068 |
11.33 |