メタデータ
| 項目 |
値 |
| Designation |
C/2020 F7 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-11-14T02:39:42.822720Z |
| Orbit solution date (soln_date, UTC) |
2023-12-28T19:42:30Z |
| Obs used |
608 |
| NEO |
- |
| M1 |
6.600 |
| K1 |
10.750 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2020-12-09.0000000 |
| e |
0.99310004 |
| q (au) |
5.331815 |
| a (au) |
772.731657 |
| i (deg) |
93.951702 |
| Ω (om, deg) |
321.886317 |
| ω (w, deg) |
227.985641 |
| M (ma, deg) |
359.984394 |
等級
散乱 + 全体線形
$$
M_a = (2.349 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
2.349 |
| n |
6.000 |
| gf |
0.977 |
| gb |
-0.693 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2020-01-04 |
2021-11-11 |
+4.9500 |
-3.771 |
| 2021-11-14 |
2023-12-20 |
-12.9005 |
+9.601 |
log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
23:13:20.00 |
-43:20:33.6 |
HIP 114814 |
28.00 |
| 2026-06-01 12:00 |
23:13:19.15 |
-43:21:26.9 |
HIP 114814 |
27.64 |
| 2026-06-02 00:00 |
23:13:18.19 |
-43:22:20.7 |
HIP 114755 |
27.07 |
| 2026-06-02 12:00 |
23:13:17.13 |
-43:23:15.0 |
HIP 114755 |
26.43 |
| 2026-06-03 00:00 |
23:13:15.97 |
-43:24:09.9 |
HIP 114755 |
25.83 |
| 2026-06-03 12:00 |
23:13:14.70 |
-43:25:05.1 |
HIP 114755 |
25.24 |
| 2026-06-04 00:00 |
23:13:13.32 |
-43:26:00.9 |
HIP 114755 |
24.69 |
| 2026-06-04 12:00 |
23:13:11.84 |
-43:26:57.2 |
HIP 114755 |
24.17 |
| 2026-06-05 00:00 |
23:13:10.26 |
-43:27:53.9 |
HIP 114755 |
23.69 |
| 2026-06-05 12:00 |
23:13:08.56 |
-43:28:51.0 |
HIP 114755 |
23.24 |
| 2026-06-06 00:00 |
23:13:06.77 |
-43:29:48.6 |
HIP 114755 |
22.84 |
| 2026-06-06 12:00 |
23:13:04.86 |
-43:30:46.7 |
HIP 114755 |
22.49 |
| 2026-06-07 00:00 |
23:13:02.85 |
-43:31:45.2 |
HIP 114755 |
22.20 |
| 2026-06-07 12:00 |
23:13:00.74 |
-43:32:44.1 |
HIP 114755 |
21.96 |
| 2026-06-08 00:00 |
23:12:58.51 |
-43:33:43.5 |
HIP 114755 |
21.78 |
| 2026-06-08 12:00 |
23:12:56.18 |
-43:34:43.3 |
HIP 114475 |
21.50 |
| 2026-06-09 00:00 |
23:12:53.74 |
-43:35:43.5 |
HIP 114475 |
20.89 |
| 2026-06-09 12:00 |
23:12:51.20 |
-43:36:44.1 |
HIP 114475 |
20.30 |
| 2026-06-10 00:00 |
23:12:48.54 |
-43:37:45.1 |
HIP 114475 |
19.74 |
| 2026-06-10 12:00 |
23:12:45.78 |
-43:38:46.6 |
HIP 114475 |
19.21 |
| 2026-06-11 00:00 |
23:12:42.91 |
-43:39:48.4 |
HIP 114475 |
18.71 |
| 2026-06-11 12:00 |
23:12:39.93 |
-43:40:50.6 |
HIP 114475 |
18.25 |
| 2026-06-12 00:00 |
23:12:36.84 |
-43:41:53.1 |
HIP 114475 |
17.84 |
| 2026-06-12 12:00 |
23:12:33.64 |
-43:42:56.1 |
HIP 114541 |
17.24 |
| 2026-06-13 00:00 |
23:12:30.33 |
-43:43:59.4 |
HIP 114541 |
16.05 |
| 2026-06-13 12:00 |
23:12:26.91 |
-43:45:03.0 |
HIP 114541 |
14.86 |
| 2026-06-14 00:00 |
23:12:23.38 |
-43:46:07.0 |
HIP 114541 |
13.65 |
| 2026-06-14 12:00 |
23:12:19.75 |
-43:47:11.4 |
HIP 114541 |
12.45 |
| 2026-06-15 00:00 |
23:12:16.00 |
-43:48:16.0 |
HIP 114541 |
11.25 |
| 2026-06-15 12:00 |
23:12:12.14 |
-43:49:21.0 |
HIP 114541 |
10.05 |
| 2026-06-16 00:00 |
23:12:08.18 |
-43:50:26.3 |
HIP 114541 |
8.88 |
| 2026-06-16 12:00 |
23:12:04.10 |
-43:51:31.9 |
HIP 114541 |
7.74 |
| 2026-06-17 00:00 |
23:11:59.91 |
-43:52:37.8 |
HIP 114541 |
6.66 |
| 2026-06-17 12:00 |
23:11:55.61 |
-43:53:44.0 |
HIP 114541 |
5.69 |
| 2026-06-18 00:00 |
23:11:51.20 |
-43:54:50.5 |
HIP 114541 |
4.91 |
| 2026-06-18 12:00 |
23:11:46.69 |
-43:55:57.2 |
HIP 114541 |
4.43 |
| 2026-06-19 00:00 |
23:11:42.06 |
-43:57:04.2 |
HIP 114541 |
4.37 |
| 2026-06-19 12:00 |
23:11:37.32 |
-43:58:11.5 |
HIP 114541 |
4.75 |
| 2026-06-20 00:00 |
23:11:32.47 |
-43:59:19.0 |
HIP 114541 |
5.50 |
| 2026-06-20 12:00 |
23:11:27.51 |
-44:00:26.7 |
HIP 114541 |
6.49 |
| 2026-06-21 00:00 |
23:11:22.44 |
-44:01:34.7 |
HIP 114541 |
7.65 |
| 2026-06-21 12:00 |
23:11:17.27 |
-44:02:42.9 |
HIP 114541 |
8.92 |
| 2026-06-22 00:00 |
23:11:11.98 |
-44:03:51.3 |
HIP 114541 |
10.26 |