メタデータ
| 項目 |
値 |
| Designation |
C/2020 S8 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-04-10T22:18:20.384640Z |
| Orbit solution date (soln_date, UTC) |
2021-08-06T00:42:41Z |
| Obs used |
591 |
| NEO |
- |
| M1 |
9.900 |
| K1 |
16.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2020-09-18T02:54:34.272000Z |
| Discovery magnitude (MPC) |
20.10 G |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2021-03-21.0000000 |
| e |
0.99139921 |
| q (au) |
2.363839 |
| a (au) |
274.839865 |
| i (deg) |
108.517979 |
| Ω (om, deg) |
24.051990 |
| ω (w, deg) |
160.334070 |
| M (ma, deg) |
359.995473 |
等級
散乱 + 全体線形
$$
M_a = (10.125 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.125 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-0.807 |
| k |
0.994 |
| 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) |
| 2026-03-26 00:00 |
04:31:01.98 |
-38:07:28.9 |
HIP 20999 |
11.56 |
| 2026-03-26 12:00 |
04:31:05.26 |
-38:05:38.5 |
HIP 20999 |
11.38 |
| 2026-03-27 00:00 |
04:31:08.62 |
-38:03:48.6 |
HIP 20999 |
11.54 |
| 2026-03-27 12:00 |
04:31:12.04 |
-38:01:59.1 |
HIP 20999 |
12.04 |
| 2026-03-28 00:00 |
04:31:15.54 |
-38:00:10.1 |
HIP 20999 |
12.83 |
| 2026-03-28 12:00 |
04:31:19.12 |
-37:58:21.5 |
HIP 20999 |
13.86 |
| 2026-03-29 00:00 |
04:31:22.76 |
-37:56:33.3 |
HIP 20999 |
15.08 |
| 2026-03-29 12:00 |
04:31:26.47 |
-37:54:45.6 |
HIP 20999 |
16.46 |
| 2026-03-30 00:00 |
04:31:30.26 |
-37:52:58.3 |
HIP 20999 |
17.94 |
| 2026-03-30 12:00 |
04:31:34.11 |
-37:51:11.5 |
HIP 20999 |
19.51 |
| 2026-03-31 00:00 |
04:31:38.03 |
-37:49:25.2 |
HIP 20999 |
21.15 |
| 2026-03-31 12:00 |
04:31:42.02 |
-37:47:39.4 |
HIP 20999 |
22.85 |
| 2026-04-01 00:00 |
04:31:46.08 |
-37:45:54.0 |
HIP 20999 |
24.58 |
| 2026-04-01 12:00 |
04:31:50.20 |
-37:44:09.1 |
HIP 20999 |
26.35 |
| 2026-04-02 00:00 |
04:31:54.40 |
-37:42:24.7 |
HIP 20999 |
28.14 |
| 2026-04-02 12:00 |
04:31:58.66 |
-37:40:40.7 |
HIP 20999 |
29.95 |
| 2026-04-03 00:00 |
04:32:02.98 |
-37:38:57.3 |
HIP 20999 |
31.78 |
| 2026-04-03 12:00 |
04:32:07.37 |
-37:37:14.4 |
HIP 20999 |
33.62 |
| 2026-04-04 00:00 |
04:32:11.82 |
-37:35:31.9 |
HIP 20999 |
35.47 |
| 2026-04-04 12:00 |
04:32:16.34 |
-37:33:50.0 |
HIP 20999 |
37.34 |
| 2026-04-05 00:00 |
04:32:20.93 |
-37:32:08.6 |
HIP 21223 |
36.66 |
| 2026-04-05 12:00 |
04:32:25.57 |
-37:30:27.7 |
HIP 21223 |
34.80 |
| 2026-04-06 00:00 |
04:32:30.28 |
-37:28:47.3 |
HIP 21223 |
32.95 |
| 2026-04-06 12:00 |
04:32:35.05 |
-37:27:07.5 |
HIP 21223 |
31.11 |
| 2026-04-07 00:00 |
04:32:39.88 |
-37:25:28.2 |
HIP 21223 |
29.29 |
| 2026-04-07 12:00 |
04:32:44.78 |
-37:23:49.4 |
HIP 21223 |
27.49 |
| 2026-04-08 00:00 |
04:32:49.73 |
-37:22:11.2 |
HIP 21223 |
25.72 |
| 2026-04-08 12:00 |
04:32:54.75 |
-37:20:33.5 |
HIP 21223 |
23.97 |
| 2026-04-09 00:00 |
04:32:59.82 |
-37:18:56.3 |
HIP 21223 |
22.25 |
| 2026-04-09 12:00 |
04:33:04.96 |
-37:17:19.8 |
HIP 21223 |
20.58 |
| 2026-04-10 00:00 |
04:33:10.15 |
-37:15:43.7 |
HIP 21223 |
18.96 |
| 2026-04-10 12:00 |
04:33:15.40 |
-37:14:08.3 |
HIP 21223 |
17.41 |
| 2026-04-11 00:00 |
04:33:20.71 |
-37:12:33.4 |
HIP 21223 |
15.95 |
| 2026-04-11 12:00 |
04:33:26.08 |
-37:10:59.1 |
HIP 21223 |
14.60 |
| 2026-04-12 00:00 |
04:33:31.50 |
-37:09:25.3 |
HIP 21223 |
13.40 |
| 2026-04-12 12:00 |
04:33:36.98 |
-37:07:52.2 |
HIP 21223 |
12.39 |
| 2026-04-13 00:00 |
04:33:42.51 |
-37:06:19.6 |
HIP 21223 |
11.63 |
| 2026-04-13 12:00 |
04:33:48.10 |
-37:04:47.6 |
HIP 21223 |
11.15 |
| 2026-04-14 00:00 |
04:33:53.75 |
-37:03:16.2 |
HIP 21223 |
10.99 |
| 2026-04-14 12:00 |
04:33:59.45 |
-37:01:45.5 |
HIP 21223 |
11.18 |
| 2026-04-15 00:00 |
04:34:05.20 |
-37:00:15.3 |
HIP 21223 |
11.69 |
| 2026-04-15 12:00 |
04:34:11.00 |
-36:58:45.7 |
HIP 21223 |
12.47 |
| 2026-04-16 00:00 |
04:34:16.86 |
-36:57:16.8 |
HIP 21223 |
13.50 |