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 · University of Arizona 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) |
| 2026-06-01 00:00 |
04:45:41.79 |
-35:31:11.4 |
HIP 22194 |
19.43 |
| 2026-06-01 12:00 |
04:45:50.01 |
-35:30:50.9 |
HIP 22194 |
19.02 |
| 2026-06-02 00:00 |
04:45:58.23 |
-35:30:31.1 |
HIP 22194 |
18.75 |
| 2026-06-02 12:00 |
04:46:06.45 |
-35:30:12.1 |
HIP 22194 |
18.62 |
| 2026-06-03 00:00 |
04:46:14.66 |
-35:29:53.9 |
HIP 22194 |
18.63 |
| 2026-06-03 12:00 |
04:46:22.88 |
-35:29:36.4 |
HIP 22194 |
18.78 |
| 2026-06-04 00:00 |
04:46:31.09 |
-35:29:19.8 |
HIP 22194 |
19.06 |
| 2026-06-04 12:00 |
04:46:39.30 |
-35:29:04.0 |
HIP 22194 |
19.48 |
| 2026-06-05 00:00 |
04:46:47.50 |
-35:28:49.0 |
HIP 22194 |
20.02 |
| 2026-06-05 12:00 |
04:46:55.71 |
-35:28:34.7 |
HIP 22194 |
20.67 |
| 2026-06-06 00:00 |
04:47:03.90 |
-35:28:21.3 |
HIP 22194 |
21.42 |
| 2026-06-06 12:00 |
04:47:12.10 |
-35:28:08.6 |
HIP 22194 |
22.25 |
| 2026-06-07 00:00 |
04:47:20.28 |
-35:27:56.8 |
HIP 22194 |
23.17 |
| 2026-06-07 12:00 |
04:47:28.47 |
-35:27:45.7 |
HIP 22194 |
24.16 |
| 2026-06-08 00:00 |
04:47:36.64 |
-35:27:35.5 |
HIP 22194 |
25.21 |
| 2026-06-08 12:00 |
04:47:44.81 |
-35:27:26.0 |
HIP 22194 |
26.31 |
| 2026-06-09 00:00 |
04:47:52.97 |
-35:27:17.4 |
HIP 22387 |
27.19 |
| 2026-06-09 12:00 |
04:48:01.12 |
-35:27:09.5 |
HIP 22387 |
26.16 |
| 2026-06-10 00:00 |
04:48:09.27 |
-35:27:02.4 |
HIP 22387 |
25.21 |
| 2026-06-10 12:00 |
04:48:17.40 |
-35:26:56.1 |
HIP 22387 |
24.35 |
| 2026-06-11 00:00 |
04:48:25.53 |
-35:26:50.7 |
HIP 22387 |
23.59 |
| 2026-06-11 12:00 |
04:48:33.65 |
-35:26:46.0 |
HIP 22387 |
22.94 |
| 2026-06-12 00:00 |
04:48:41.75 |
-35:26:42.1 |
HIP 22387 |
22.40 |
| 2026-06-12 12:00 |
04:48:49.84 |
-35:26:39.0 |
HIP 22387 |
21.99 |
| 2026-06-13 00:00 |
04:48:57.92 |
-35:26:36.7 |
HIP 22387 |
21.72 |
| 2026-06-13 12:00 |
04:49:05.99 |
-35:26:35.2 |
HIP 22387 |
21.58 |
| 2026-06-14 00:00 |
04:49:14.05 |
-35:26:34.6 |
HIP 22387 |
21.57 |
| 2026-06-14 12:00 |
04:49:22.09 |
-35:26:34.7 |
HIP 22451 |
21.06 |
| 2026-06-15 00:00 |
04:49:30.12 |
-35:26:35.6 |
HIP 22451 |
20.66 |
| 2026-06-15 12:00 |
04:49:38.13 |
-35:26:37.3 |
HIP 22451 |
20.39 |
| 2026-06-16 00:00 |
04:49:46.13 |
-35:26:39.7 |
HIP 22451 |
20.26 |
| 2026-06-16 12:00 |
04:49:54.11 |
-35:26:43.0 |
HIP 22451 |
20.28 |
| 2026-06-17 00:00 |
04:50:02.08 |
-35:26:47.1 |
HIP 22451 |
20.44 |
| 2026-06-17 12:00 |
04:50:10.03 |
-35:26:52.0 |
HIP 22451 |
20.74 |
| 2026-06-18 00:00 |
04:50:17.96 |
-35:26:57.6 |
HIP 22451 |
21.17 |
| 2026-06-18 12:00 |
04:50:25.87 |
-35:27:04.1 |
HIP 22451 |
21.73 |
| 2026-06-19 00:00 |
04:50:33.76 |
-35:27:11.3 |
HIP 22451 |
22.40 |
| 2026-06-19 12:00 |
04:50:41.64 |
-35:27:19.3 |
HIP 22451 |
23.18 |
| 2026-06-20 00:00 |
04:50:49.49 |
-35:27:28.1 |
HIP 22451 |
24.04 |
| 2026-06-20 12:00 |
04:50:57.32 |
-35:27:37.7 |
HIP 22602 |
24.82 |
| 2026-06-21 00:00 |
04:51:05.14 |
-35:27:48.1 |
HIP 22602 |
24.07 |
| 2026-06-21 12:00 |
04:51:12.93 |
-35:27:59.2 |
HIP 22602 |
23.39 |
| 2026-06-22 00:00 |
04:51:20.70 |
-35:28:11.1 |
HIP 22602 |
22.80 |