メタデータ
| 項目 |
値 |
| Designation |
C/2020 X4 (Leonard) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-11-14T11:24:14.964480Z |
| Orbit solution date (soln_date, UTC) |
2021-09-20T00:12:50Z |
| Obs used |
113 |
| NEO |
- |
| M1 |
7.200 |
| K1 |
13.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-12-14T02:02:54.758400Z |
| Discovery magnitude (MPC) |
20.00 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) |
2021-02-28.0000000 |
| e |
0.87940102 |
| q (au) |
5.205810 |
| a (au) |
43.166284 |
| i (deg) |
80.491366 |
| Ω (om, deg) |
161.905337 |
| ω (w, deg) |
139.911326 |
| M (ma, deg) |
0.366726 |
等級
散乱 + 全体線形
$$
M_a = (4.783 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
4.783 |
| n |
6.000 |
| gf |
0.999 |
| 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) |
| 2026-09-25 00:00 |
03:31:56.85 |
-58:58:00.2 |
HIP 16542 |
21.33 |
| 2026-09-25 12:00 |
03:31:50.29 |
-58:59:51.9 |
HIP 16542 |
23.38 |
| 2026-09-26 00:00 |
03:31:43.62 |
-59:01:43.0 |
HIP 16542 |
25.42 |
| 2026-09-26 12:00 |
03:31:36.83 |
-59:03:33.4 |
HIP 16542 |
27.45 |
| 2026-09-27 00:00 |
03:31:29.91 |
-59:05:23.2 |
HIP 16542 |
29.49 |
| 2026-09-27 12:00 |
03:31:22.87 |
-59:07:12.2 |
HIP 16542 |
31.52 |
| 2026-09-28 00:00 |
03:31:15.72 |
-59:09:00.5 |
HIP 16542 |
33.54 |
| 2026-09-28 12:00 |
03:31:08.44 |
-59:10:48.2 |
HIP 16756 |
34.32 |
| 2026-09-29 00:00 |
03:31:01.04 |
-59:12:35.0 |
HIP 16756 |
35.03 |
| 2026-09-29 12:00 |
03:30:53.53 |
-59:14:21.2 |
HIP 16026 |
34.88 |
| 2026-09-30 00:00 |
03:30:45.89 |
-59:16:06.6 |
HIP 16026 |
33.75 |
| 2026-09-30 12:00 |
03:30:38.14 |
-59:17:51.3 |
HIP 16026 |
32.70 |
| 2026-10-01 00:00 |
03:30:30.27 |
-59:19:35.2 |
HIP 16026 |
31.73 |
| 2026-10-01 12:00 |
03:30:22.29 |
-59:21:18.3 |
HIP 16026 |
30.84 |
| 2026-10-02 00:00 |
03:30:14.19 |
-59:23:00.7 |
HIP 16417 |
29.77 |
| 2026-10-02 12:00 |
03:30:05.97 |
-59:24:42.2 |
HIP 16417 |
28.50 |
| 2026-10-03 00:00 |
03:29:57.65 |
-59:26:23.0 |
HIP 16417 |
27.33 |
| 2026-10-03 12:00 |
03:29:49.20 |
-59:28:03.0 |
HIP 16417 |
26.28 |
| 2026-10-04 00:00 |
03:29:40.65 |
-59:29:42.1 |
HIP 16417 |
25.36 |
| 2026-10-04 12:00 |
03:29:31.98 |
-59:31:20.5 |
HIP 16417 |
24.59 |
| 2026-10-05 00:00 |
03:29:23.20 |
-59:32:58.0 |
HIP 16417 |
23.97 |
| 2026-10-05 12:00 |
03:29:14.31 |
-59:34:34.6 |
HIP 16417 |
23.51 |
| 2026-10-06 00:00 |
03:29:05.32 |
-59:36:10.4 |
HIP 16204 |
22.55 |
| 2026-10-06 12:00 |
03:28:56.21 |
-59:37:45.4 |
HIP 16204 |
20.88 |
| 2026-10-07 00:00 |
03:28:47.00 |
-59:39:19.5 |
HIP 16204 |
19.28 |
| 2026-10-07 12:00 |
03:28:37.68 |
-59:40:52.7 |
HIP 16204 |
17.76 |
| 2026-10-08 00:00 |
03:28:28.25 |
-59:42:25.0 |
HIP 16204 |
16.36 |
| 2026-10-08 12:00 |
03:28:18.72 |
-59:43:56.4 |
HIP 16204 |
15.08 |
| 2026-10-09 00:00 |
03:28:09.09 |
-59:45:26.9 |
HIP 16204 |
13.99 |
| 2026-10-09 12:00 |
03:27:59.35 |
-59:46:56.5 |
HIP 16204 |
13.10 |
| 2026-10-10 00:00 |
03:27:49.51 |
-59:48:25.2 |
HIP 16204 |
12.47 |
| 2026-10-10 12:00 |
03:27:39.57 |
-59:49:52.9 |
HIP 16204 |
12.14 |
| 2026-10-11 00:00 |
03:27:29.53 |
-59:51:19.7 |
HIP 16204 |
12.12 |
| 2026-10-11 12:00 |
03:27:19.40 |
-59:52:45.6 |
HIP 16204 |
12.42 |
| 2026-10-12 00:00 |
03:27:09.17 |
-59:54:10.5 |
HIP 16204 |
13.02 |
| 2026-10-12 12:00 |
03:26:58.84 |
-59:55:34.4 |
HIP 16204 |
13.86 |
| 2026-10-13 00:00 |
03:26:48.42 |
-59:56:57.4 |
HIP 16204 |
14.92 |
| 2026-10-13 12:00 |
03:26:37.90 |
-59:58:19.4 |
HIP 16204 |
16.14 |
| 2026-10-14 00:00 |
03:26:27.30 |
-59:59:40.4 |
HIP 16204 |
17.49 |
| 2026-10-14 12:00 |
03:26:16.60 |
-60:01:00.4 |
HIP 16204 |
18.94 |
| 2026-10-15 00:00 |
03:26:05.81 |
-60:02:19.5 |
HIP 16204 |
20.47 |
| 2026-10-15 12:00 |
03:25:54.94 |
-60:03:37.5 |
HIP 16204 |
22.06 |
| 2026-10-16 00:00 |
03:25:43.98 |
-60:04:54.5 |
HIP 16204 |
23.70 |