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) |
| 2026-05-12 00:00 |
02:55:05.23 |
-51:39:50.7 |
HIP 13485 |
16.22 |
| 2026-05-12 12:00 |
02:55:21.71 |
-51:39:59.5 |
HIP 13575 |
17.80 |
| 2026-05-13 00:00 |
02:55:38.19 |
-51:40:09.2 |
HIP 13575 |
18.46 |
| 2026-05-13 12:00 |
02:55:54.66 |
-51:40:19.8 |
HIP 13575 |
19.42 |
| 2026-05-14 00:00 |
02:56:11.13 |
-51:40:31.3 |
HIP 13575 |
20.63 |
| 2026-05-14 12:00 |
02:56:27.58 |
-51:40:43.7 |
HIP 13575 |
22.07 |
| 2026-05-15 00:00 |
02:56:44.03 |
-51:40:57.0 |
HIP 13575 |
23.68 |
| 2026-05-15 12:00 |
02:57:00.46 |
-51:41:11.2 |
HIP 13575 |
25.43 |
| 2026-05-16 00:00 |
02:57:16.88 |
-51:41:26.2 |
HIP 13575 |
27.30 |
| 2026-05-16 12:00 |
02:57:33.29 |
-51:41:42.2 |
HIP 13889 |
26.88 |
| 2026-05-17 00:00 |
02:57:49.69 |
-51:41:59.1 |
HIP 13889 |
25.59 |
| 2026-05-17 12:00 |
02:58:06.08 |
-51:42:16.9 |
HIP 13889 |
24.48 |
| 2026-05-18 00:00 |
02:58:22.45 |
-51:42:35.6 |
HIP 13889 |
23.58 |
| 2026-05-18 12:00 |
02:58:38.81 |
-51:42:55.2 |
HIP 13889 |
22.92 |
| 2026-05-19 00:00 |
02:58:55.15 |
-51:43:15.7 |
HIP 13889 |
22.51 |
| 2026-05-19 12:00 |
02:59:11.48 |
-51:43:37.1 |
HIP 13889 |
22.36 |
| 2026-05-20 00:00 |
02:59:27.79 |
-51:43:59.4 |
HIP 13889 |
22.49 |
| 2026-05-20 12:00 |
02:59:44.08 |
-51:44:22.6 |
HIP 13889 |
22.89 |
| 2026-05-21 00:00 |
03:00:00.35 |
-51:44:46.7 |
HIP 13889 |
23.54 |
| 2026-05-21 12:00 |
03:00:16.61 |
-51:45:11.7 |
HIP 13889 |
24.43 |
| 2026-05-22 00:00 |
03:00:32.85 |
-51:45:37.6 |
HIP 13889 |
25.53 |
| 2026-05-22 12:00 |
03:00:49.06 |
-51:46:04.4 |
HIP 13889 |
26.80 |
| 2026-05-23 00:00 |
03:01:05.26 |
-51:46:32.0 |
HIP 13889 |
28.24 |
| 2026-05-23 12:00 |
03:01:21.44 |
-51:47:00.6 |
HIP 13889 |
29.81 |
| 2026-05-24 00:00 |
03:01:37.59 |
-51:47:30.0 |
HIP 14257 |
30.81 |
| 2026-05-24 12:00 |
03:01:53.73 |
-51:48:00.4 |
HIP 14257 |
29.59 |
| 2026-05-25 00:00 |
03:02:09.84 |
-51:48:31.6 |
HIP 14257 |
28.56 |
| 2026-05-25 12:00 |
03:02:25.92 |
-51:49:03.7 |
HIP 14257 |
27.75 |
| 2026-05-26 00:00 |
03:02:41.99 |
-51:49:36.7 |
HIP 14257 |
27.17 |
| 2026-05-26 12:00 |
03:02:58.02 |
-51:50:10.6 |
HIP 14251 |
25.90 |
| 2026-05-27 00:00 |
03:03:14.04 |
-51:50:45.3 |
HIP 14251 |
24.71 |
| 2026-05-27 12:00 |
03:03:30.03 |
-51:51:21.0 |
HIP 14251 |
23.72 |
| 2026-05-28 00:00 |
03:03:45.99 |
-51:51:57.5 |
HIP 14251 |
22.95 |
| 2026-05-28 12:00 |
03:04:01.93 |
-51:52:34.9 |
HIP 14251 |
22.43 |
| 2026-05-29 00:00 |
03:04:17.83 |
-51:53:13.2 |
HIP 14251 |
22.17 |
| 2026-05-29 12:00 |
03:04:33.72 |
-51:53:52.3 |
HIP 14251 |
22.18 |
| 2026-05-30 00:00 |
03:04:49.57 |
-51:54:32.4 |
HIP 14251 |
22.46 |
| 2026-05-30 12:00 |
03:05:05.39 |
-51:55:13.3 |
HIP 14251 |
23.00 |
| 2026-05-31 00:00 |
03:05:21.19 |
-51:55:55.1 |
HIP 14251 |
23.79 |
| 2026-05-31 12:00 |
03:05:36.96 |
-51:56:37.7 |
HIP 14251 |
24.79 |
| 2026-06-01 00:00 |
03:05:52.69 |
-51:57:21.2 |
HIP 14251 |
25.98 |
| 2026-06-01 12:00 |
03:06:08.40 |
-51:58:05.6 |
HIP 14251 |
27.35 |
| 2026-06-02 00:00 |
03:06:24.07 |
-51:58:50.9 |
HIP 14251 |
28.85 |