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 · 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 |
1.000 |
| 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) |
| 2026-03-26 00:00 |
02:30:08.07 |
-52:29:37.1 |
HIP 11555 |
11.54 |
| 2026-03-26 12:00 |
02:30:22.56 |
-52:28:28.7 |
HIP 11555 |
13.72 |
| 2026-03-27 00:00 |
02:30:37.10 |
-52:27:20.9 |
HIP 11555 |
16.00 |
| 2026-03-27 12:00 |
02:30:51.69 |
-52:26:13.8 |
HIP 11555 |
18.34 |
| 2026-03-28 00:00 |
02:31:06.32 |
-52:25:07.5 |
HIP 11555 |
20.72 |
| 2026-03-28 12:00 |
02:31:21.01 |
-52:24:01.8 |
HIP 11555 |
23.13 |
| 2026-03-29 00:00 |
02:31:35.74 |
-52:22:56.9 |
HIP 11702 |
23.69 |
| 2026-03-29 12:00 |
02:31:50.52 |
-52:21:52.7 |
HIP 11702 |
23.36 |
| 2026-03-30 00:00 |
02:32:05.34 |
-52:20:49.2 |
HIP 11702 |
23.31 |
| 2026-03-30 12:00 |
02:32:20.21 |
-52:19:46.5 |
HIP 11702 |
23.54 |
| 2026-03-31 00:00 |
02:32:35.13 |
-52:18:44.5 |
HIP 11877 |
23.18 |
| 2026-03-31 12:00 |
02:32:50.09 |
-52:17:43.2 |
HIP 11877 |
21.70 |
| 2026-04-01 00:00 |
02:33:05.09 |
-52:16:42.6 |
HIP 11877 |
20.43 |
| 2026-04-01 12:00 |
02:33:20.13 |
-52:15:42.8 |
HIP 11877 |
19.42 |
| 2026-04-02 00:00 |
02:33:35.22 |
-52:14:43.7 |
HIP 11877 |
18.71 |
| 2026-04-02 12:00 |
02:33:50.35 |
-52:13:45.3 |
HIP 11877 |
18.34 |
| 2026-04-03 00:00 |
02:34:05.52 |
-52:12:47.7 |
HIP 11877 |
18.32 |
| 2026-04-03 12:00 |
02:34:20.73 |
-52:11:50.9 |
HIP 11877 |
18.66 |
| 2026-04-04 00:00 |
02:34:35.98 |
-52:10:54.7 |
HIP 11877 |
19.34 |
| 2026-04-04 12:00 |
02:34:51.26 |
-52:09:59.4 |
HIP 11877 |
20.33 |
| 2026-04-05 00:00 |
02:35:06.59 |
-52:09:04.8 |
HIP 11877 |
21.58 |
| 2026-04-05 12:00 |
02:35:21.96 |
-52:08:11.0 |
HIP 11963 |
22.44 |
| 2026-04-06 00:00 |
02:35:37.36 |
-52:07:17.9 |
HIP 11963 |
22.75 |
| 2026-04-06 12:00 |
02:35:52.80 |
-52:06:25.6 |
HIP 11963 |
23.35 |
| 2026-04-07 00:00 |
02:36:08.28 |
-52:05:34.1 |
HIP 11963 |
24.22 |
| 2026-04-07 12:00 |
02:36:23.80 |
-52:04:43.3 |
HIP 12296 |
24.34 |
| 2026-04-08 00:00 |
02:36:39.34 |
-52:03:53.3 |
HIP 12296 |
23.20 |
| 2026-04-08 12:00 |
02:36:54.93 |
-52:03:04.1 |
HIP 12296 |
22.29 |
| 2026-04-09 00:00 |
02:37:10.55 |
-52:02:15.7 |
HIP 12296 |
21.61 |
| 2026-04-09 12:00 |
02:37:26.20 |
-52:01:28.0 |
HIP 12296 |
21.20 |
| 2026-04-10 00:00 |
02:37:41.88 |
-52:00:41.2 |
HIP 12296 |
21.07 |
| 2026-04-10 12:00 |
02:37:57.60 |
-51:59:55.1 |
HIP 12296 |
21.23 |
| 2026-04-11 00:00 |
02:38:13.35 |
-51:59:09.9 |
HIP 12296 |
21.68 |
| 2026-04-11 12:00 |
02:38:29.13 |
-51:58:25.4 |
HIP 12471 |
21.97 |
| 2026-04-12 00:00 |
02:38:44.94 |
-51:57:41.7 |
HIP 12471 |
19.51 |
| 2026-04-12 12:00 |
02:39:00.78 |
-51:56:58.9 |
HIP 12471 |
17.08 |
| 2026-04-13 00:00 |
02:39:16.65 |
-51:56:16.8 |
HIP 12471 |
14.69 |
| 2026-04-13 12:00 |
02:39:32.54 |
-51:55:35.6 |
HIP 12471 |
12.36 |
| 2026-04-14 00:00 |
02:39:48.47 |
-51:54:55.1 |
HIP 12471 |
10.15 |
| 2026-04-14 12:00 |
02:40:04.43 |
-51:54:15.5 |
HIP 12471 |
8.16 |
| 2026-04-15 00:00 |
02:40:20.41 |
-51:53:36.7 |
HIP 12471 |
6.56 |
| 2026-04-15 12:00 |
02:40:36.41 |
-51:52:58.8 |
HIP 12471 |
5.73 |
| 2026-04-16 00:00 |
02:40:52.45 |
-51:52:21.6 |
HIP 12471 |
5.98 |