メタデータ
| 項目 |
値 |
| Designation |
C/2021 G1 (Leonard) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-07-22T06:47:31.761600Z |
| Orbit solution date (soln_date, UTC) |
2025-01-14T17:42:12Z |
| Obs used |
54 |
| NEO |
- |
| M1 |
13.700 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-04-11T07:50:24.892800Z |
| Discovery magnitude (MPC) |
21.72 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) |
2021-04-21.0000000 |
| e |
0.95490157 |
| q (au) |
3.423704 |
| a (au) |
75.916250 |
| i (deg) |
131.566251 |
| Ω (om, deg) |
270.695657 |
| ω (w, deg) |
107.498712 |
| M (ma, deg) |
359.862493 |
等級
散乱 + 全体線形
$$
M_a = (19.995 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
19.995 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.800 |
| 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) |
| 2026-09-20 00:00 |
04:10:49.25 |
-15:56:49.3 |
HIP 19512 |
1.80 |
| 2026-09-20 12:00 |
04:10:44.40 |
-15:58:30.0 |
HIP 19512 |
3.62 |
| 2026-09-21 00:00 |
04:10:39.48 |
-16:00:10.6 |
HIP 19512 |
5.60 |
| 2026-09-21 12:00 |
04:10:34.48 |
-16:01:51.1 |
HIP 19512 |
7.62 |
| 2026-09-22 00:00 |
04:10:29.41 |
-16:03:31.6 |
HIP 19512 |
9.67 |
| 2026-09-22 12:00 |
04:10:24.26 |
-16:05:11.9 |
HIP 19512 |
11.73 |
| 2026-09-23 00:00 |
04:10:19.04 |
-16:06:52.2 |
HIP 19512 |
13.81 |
| 2026-09-23 12:00 |
04:10:13.74 |
-16:08:32.3 |
HIP 19512 |
15.90 |
| 2026-09-24 00:00 |
04:10:08.37 |
-16:10:12.4 |
HIP 19398 |
17.74 |
| 2026-09-24 12:00 |
04:10:02.93 |
-16:11:52.3 |
HIP 19398 |
15.63 |
| 2026-09-25 00:00 |
04:09:57.41 |
-16:13:32.1 |
HIP 19398 |
13.52 |
| 2026-09-25 12:00 |
04:09:51.82 |
-16:15:11.8 |
HIP 19398 |
11.39 |
| 2026-09-26 00:00 |
04:09:46.16 |
-16:16:51.3 |
HIP 19398 |
9.26 |
| 2026-09-26 12:00 |
04:09:40.42 |
-16:18:30.7 |
HIP 19398 |
7.13 |
| 2026-09-27 00:00 |
04:09:34.61 |
-16:20:09.9 |
HIP 19398 |
5.01 |
| 2026-09-27 12:00 |
04:09:28.73 |
-16:21:49.0 |
HIP 19398 |
2.93 |
| 2026-09-28 00:00 |
04:09:22.78 |
-16:23:27.9 |
HIP 19398 |
1.23 |
| 2026-09-28 12:00 |
04:09:16.76 |
-16:25:06.7 |
HIP 19398 |
1.98 |
| 2026-09-29 00:00 |
04:09:10.66 |
-16:26:45.2 |
HIP 19383 |
2.85 |
| 2026-09-29 12:00 |
04:09:04.50 |
-16:28:23.6 |
HIP 19383 |
4.47 |
| 2026-09-30 00:00 |
04:08:58.26 |
-16:30:01.8 |
HIP 19383 |
6.45 |
| 2026-09-30 12:00 |
04:08:51.95 |
-16:31:39.8 |
HIP 19383 |
8.55 |
| 2026-10-01 00:00 |
04:08:45.57 |
-16:33:17.5 |
HIP 19383 |
10.71 |
| 2026-10-01 12:00 |
04:08:39.13 |
-16:34:55.1 |
HIP 19383 |
12.90 |
| 2026-10-02 00:00 |
04:08:32.61 |
-16:36:32.4 |
HIP 19383 |
15.11 |
| 2026-10-02 12:00 |
04:08:26.02 |
-16:38:09.5 |
HIP 19383 |
17.34 |
| 2026-10-03 00:00 |
04:08:19.37 |
-16:39:46.4 |
HIP 19383 |
19.58 |
| 2026-10-03 12:00 |
04:08:12.65 |
-16:41:23.0 |
HIP 19383 |
21.83 |
| 2026-10-04 00:00 |
04:08:05.85 |
-16:42:59.4 |
HIP 19383 |
24.10 |
| 2026-10-04 12:00 |
04:07:58.99 |
-16:44:35.5 |
HIP 19383 |
26.38 |
| 2026-10-05 00:00 |
04:07:52.06 |
-16:46:11.4 |
HIP 19383 |
28.66 |
| 2026-10-05 12:00 |
04:07:45.07 |
-16:47:46.9 |
HIP 19383 |
30.95 |
| 2026-10-06 00:00 |
04:07:38.01 |
-16:49:22.2 |
HIP 19383 |
33.26 |
| 2026-10-06 12:00 |
04:07:30.88 |
-16:50:57.2 |
HIP 19383 |
35.57 |
| 2026-10-07 00:00 |
04:07:23.68 |
-16:52:31.9 |
HIP 19383 |
37.89 |
| 2026-10-07 12:00 |
04:07:16.42 |
-16:54:06.3 |
HIP 19383 |
40.22 |
| 2026-10-08 00:00 |
04:07:09.10 |
-16:55:40.4 |
HIP 19383 |
42.56 |
| 2026-10-08 12:00 |
04:07:01.71 |
-16:57:14.2 |
HIP 19383 |
44.90 |
| 2026-10-09 00:00 |
04:06:54.26 |
-16:58:47.6 |
HIP 18990 |
46.07 |
| 2026-10-09 12:00 |
04:06:46.74 |
-17:00:20.7 |
HIP 18990 |
45.37 |
| 2026-10-10 00:00 |
04:06:39.16 |
-17:01:53.5 |
HIP 18990 |
44.76 |
| 2026-10-10 12:00 |
04:06:31.51 |
-17:03:25.9 |
HIP 18990 |
44.26 |
| 2026-10-11 00:00 |
04:06:23.81 |
-17:04:57.9 |
HIP 18990 |
43.88 |