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 |
0.970 |
| gb |
-0.676 |
| k |
1.000 |
| δ90 |
9.976 |
| 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) |
| 2026-05-12 00:00 |
23:12:32.43 |
-42:52:47.0 |
HIP 114636 |
10.74 |
| 2026-05-12 12:00 |
23:12:35.47 |
-42:53:16.4 |
HIP 114636 |
10.55 |
| 2026-05-13 00:00 |
23:12:38.42 |
-42:53:46.4 |
HIP 114636 |
10.43 |
| 2026-05-13 12:00 |
23:12:41.28 |
-42:54:17.1 |
HIP 114636 |
10.38 |
| 2026-05-14 00:00 |
23:12:44.05 |
-42:54:48.4 |
HIP 114636 |
10.40 |
| 2026-05-14 12:00 |
23:12:46.73 |
-42:55:20.5 |
HIP 114636 |
10.50 |
| 2026-05-15 00:00 |
23:12:49.32 |
-42:55:53.2 |
HIP 114636 |
10.66 |
| 2026-05-15 12:00 |
23:12:51.82 |
-42:56:26.6 |
HIP 114636 |
10.88 |
| 2026-05-16 00:00 |
23:12:54.22 |
-42:57:00.6 |
HIP 114636 |
11.17 |
| 2026-05-16 12:00 |
23:12:56.54 |
-42:57:35.3 |
HIP 114636 |
11.51 |
| 2026-05-17 00:00 |
23:12:58.75 |
-42:58:10.7 |
HIP 114636 |
11.90 |
| 2026-05-17 12:00 |
23:13:00.88 |
-42:58:46.7 |
HIP 114636 |
12.33 |
| 2026-05-18 00:00 |
23:13:02.91 |
-42:59:23.4 |
HIP 114636 |
12.81 |
| 2026-05-18 12:00 |
23:13:04.84 |
-43:00:00.7 |
HIP 114636 |
13.32 |
| 2026-05-19 00:00 |
23:13:06.68 |
-43:00:38.6 |
HIP 114636 |
13.86 |
| 2026-05-19 12:00 |
23:13:08.43 |
-43:01:17.2 |
HIP 114636 |
14.43 |
| 2026-05-20 00:00 |
23:13:10.07 |
-43:01:56.4 |
HIP 114636 |
15.03 |
| 2026-05-20 12:00 |
23:13:11.63 |
-43:02:36.3 |
HIP 114636 |
15.65 |
| 2026-05-21 00:00 |
23:13:13.08 |
-43:03:16.7 |
HIP 114636 |
16.29 |
| 2026-05-21 12:00 |
23:13:14.44 |
-43:03:57.8 |
HIP 114636 |
16.95 |
| 2026-05-22 00:00 |
23:13:15.70 |
-43:04:39.5 |
HIP 114636 |
17.63 |
| 2026-05-22 12:00 |
23:13:16.86 |
-43:05:21.8 |
HIP 114636 |
18.32 |
| 2026-05-23 00:00 |
23:13:17.93 |
-43:06:04.7 |
HIP 114636 |
19.02 |
| 2026-05-23 12:00 |
23:13:18.89 |
-43:06:48.2 |
HIP 114636 |
19.74 |
| 2026-05-24 00:00 |
23:13:19.76 |
-43:07:32.2 |
HIP 114636 |
20.47 |
| 2026-05-24 12:00 |
23:13:20.53 |
-43:08:16.9 |
HIP 114636 |
21.22 |
| 2026-05-25 00:00 |
23:13:21.20 |
-43:09:02.1 |
HIP 114636 |
21.97 |
| 2026-05-25 12:00 |
23:13:21.77 |
-43:09:47.9 |
HIP 114636 |
22.73 |
| 2026-05-26 00:00 |
23:13:22.24 |
-43:10:34.3 |
HIP 114636 |
23.50 |
| 2026-05-26 12:00 |
23:13:22.61 |
-43:11:21.3 |
HIP 114636 |
24.29 |
| 2026-05-27 00:00 |
23:13:22.88 |
-43:12:08.8 |
HIP 114636 |
25.08 |
| 2026-05-27 12:00 |
23:13:23.05 |
-43:12:56.8 |
HIP 114636 |
25.88 |
| 2026-05-28 00:00 |
23:13:23.12 |
-43:13:45.5 |
HIP 114636 |
26.69 |
| 2026-05-28 12:00 |
23:13:23.09 |
-43:14:34.6 |
HIP 114636 |
27.51 |
| 2026-05-29 00:00 |
23:13:22.96 |
-43:15:24.3 |
HIP 114636 |
28.34 |
| 2026-05-29 12:00 |
23:13:22.72 |
-43:16:14.6 |
HIP 114636 |
29.18 |
| 2026-05-30 00:00 |
23:13:22.38 |
-43:17:05.3 |
HIP 114814 |
29.76 |
| 2026-05-30 12:00 |
23:13:21.94 |
-43:17:56.6 |
HIP 114814 |
29.28 |
| 2026-05-31 00:00 |
23:13:21.40 |
-43:18:48.4 |
HIP 114814 |
28.82 |
| 2026-05-31 12:00 |
23:13:20.75 |
-43:19:40.7 |
HIP 114814 |
28.40 |
| 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 |