C/2020 X4 (Leonard)
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) |
| 2026-02-03 00:00 |
02:11:56.04 |
-55:12:41.5 |
HIP 10547 |
33.71 |
| 2026-02-03 12:00 |
02:12:01.90 |
-55:10:49.0 |
HIP 10547 |
33.18 |
| 2026-02-04 00:00 |
02:12:07.88 |
-55:08:56.5 |
HIP 10547 |
32.75 |
| 2026-02-04 12:00 |
02:12:13.97 |
-55:07:04.1 |
HIP 10134 |
31.71 |
| 2026-02-05 00:00 |
02:12:20.18 |
-55:05:11.8 |
HIP 10134 |
30.63 |
| 2026-02-05 12:00 |
02:12:26.50 |
-55:03:19.7 |
HIP 10134 |
29.66 |
| 2026-02-06 00:00 |
02:12:32.94 |
-55:01:27.7 |
HIP 10134 |
28.82 |
| 2026-02-06 12:00 |
02:12:39.49 |
-54:59:35.8 |
HIP 10134 |
28.12 |
| 2026-02-07 00:00 |
02:12:46.16 |
-54:57:44.0 |
HIP 10134 |
27.58 |
| 2026-02-07 12:00 |
02:12:52.93 |
-54:55:52.4 |
HIP 10134 |
27.21 |
| 2026-02-08 00:00 |
02:12:59.82 |
-54:54:01.0 |
HIP 10134 |
27.01 |
| 2026-02-08 12:00 |
02:13:06.83 |
-54:52:09.7 |
HIP 10134 |
27.00 |
| 2026-02-09 00:00 |
02:13:13.94 |
-54:50:18.6 |
HIP 10461 |
27.15 |
| 2026-02-09 12:00 |
02:13:21.16 |
-54:48:27.6 |
HIP 10461 |
25.03 |
| 2026-02-10 00:00 |
02:13:28.49 |
-54:46:36.9 |
HIP 10461 |
22.90 |
| 2026-02-10 12:00 |
02:13:35.94 |
-54:44:46.3 |
HIP 10461 |
20.77 |
| 2026-02-11 00:00 |
02:13:43.49 |
-54:42:55.9 |
HIP 10461 |
18.63 |
| 2026-02-11 12:00 |
02:13:51.15 |
-54:41:05.8 |
HIP 10461 |
16.49 |
| 2026-02-12 00:00 |
02:13:58.92 |
-54:39:15.9 |
HIP 10461 |
14.34 |
| 2026-02-12 12:00 |
02:14:06.79 |
-54:37:26.1 |
HIP 10461 |
12.19 |
| 2026-02-13 00:00 |
02:14:14.77 |
-54:35:36.7 |
HIP 10461 |
10.03 |
| 2026-02-13 12:00 |
02:14:22.86 |
-54:33:47.4 |
HIP 10461 |
7.86 |
| 2026-02-14 00:00 |
02:14:31.06 |
-54:31:58.4 |
HIP 10461 |
5.69 |
| 2026-02-14 12:00 |
02:14:39.35 |
-54:30:09.7 |
HIP 10461 |
3.52 |
| 2026-02-15 00:00 |
02:14:47.76 |
-54:28:21.2 |
HIP 10461 |
1.34 |
| 2026-02-15 12:00 |
02:14:56.26 |
-54:26:33.0 |
HIP 10461 |
0.87 |
| 2026-02-16 00:00 |
02:15:04.87 |
-54:24:45.1 |
HIP 10461 |
3.05 |
| 2026-02-16 12:00 |
02:15:13.58 |
-54:22:57.5 |
HIP 10461 |
5.25 |
| 2026-02-17 00:00 |
02:15:22.40 |
-54:21:10.1 |
HIP 10461 |
7.45 |
| 2026-02-17 12:00 |
02:15:31.31 |
-54:19:23.1 |
HIP 10461 |
9.66 |
| 2026-02-18 00:00 |
02:15:40.32 |
-54:17:36.3 |
HIP 10461 |
11.87 |
| 2026-02-18 12:00 |
02:15:49.44 |
-54:15:49.9 |
HIP 10461 |
14.09 |
| 2026-02-19 00:00 |
02:15:58.65 |
-54:14:03.8 |
HIP 10461 |
16.31 |
| 2026-02-19 12:00 |
02:16:07.96 |
-54:12:18.0 |
HIP 10688 |
18.01 |
| 2026-02-20 00:00 |
02:16:17.37 |
-54:10:32.6 |
HIP 10688 |
15.80 |
| 2026-02-20 12:00 |
02:16:26.88 |
-54:08:47.5 |
HIP 10688 |
13.58 |
| 2026-02-21 00:00 |
02:16:36.48 |
-54:07:02.8 |
HIP 10688 |
11.36 |
| 2026-02-21 12:00 |
02:16:46.18 |
-54:05:18.4 |
HIP 10688 |
9.14 |
| 2026-02-22 00:00 |
02:16:55.97 |
-54:03:34.4 |
HIP 10688 |
6.94 |
| 2026-02-22 12:00 |
02:17:05.85 |
-54:01:50.8 |
HIP 10688 |
4.77 |
| 2026-02-23 00:00 |
02:17:15.83 |
-54:00:07.6 |
HIP 10688 |
2.72 |
| 2026-02-23 12:00 |
02:17:25.90 |
-53:58:24.7 |
HIP 10688 |
1.51 |
| 2026-02-24 00:00 |
02:17:36.07 |
-53:56:42.2 |
HIP 10688 |
2.72 |