メタデータ
| 項目 |
値 |
| Designation |
C/2020 B2 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-01-26T06:53:39.419520Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:34:04Z |
| Obs used |
106 |
| NEO |
- |
| M1 |
17.200 |
| K1 |
4.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2020-02-04.0000000 |
| e |
0.95922180 |
| q (au) |
2.768047 |
| a (au) |
67.880568 |
| i (deg) |
55.704138 |
| Ω (om, deg) |
354.338868 |
| ω (w, deg) |
143.629671 |
| M (ma, deg) |
0.015355 |
等級
散乱 + 全体線形
$$
M_a = (16.433 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
16.433 |
| n |
2.000 |
| gf |
0.999 |
| gb |
-1.000 |
| k |
0.998 |
| 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 |
20:17:56.26 |
-76:39:53.2 |
HIP 99466 |
23.30 |
| 2026-03-26 12:00 |
20:18:14.01 |
-76:41:00.0 |
HIP 99466 |
24.46 |
| 2026-03-27 00:00 |
20:18:31.57 |
-76:42:07.2 |
HIP 99466 |
25.65 |
| 2026-03-27 12:00 |
20:18:48.95 |
-76:43:14.8 |
HIP 99466 |
26.86 |
| 2026-03-28 00:00 |
20:19:06.13 |
-76:44:22.8 |
HIP 99466 |
28.08 |
| 2026-03-28 12:00 |
20:19:23.12 |
-76:45:31.2 |
HIP 99551 |
28.59 |
| 2026-03-29 00:00 |
20:19:39.92 |
-76:46:39.9 |
HIP 99551 |
28.85 |
| 2026-03-29 12:00 |
20:19:56.53 |
-76:47:49.1 |
HIP 99551 |
29.16 |
| 2026-03-30 00:00 |
20:20:12.94 |
-76:48:58.7 |
HIP 99551 |
29.54 |
| 2026-03-30 12:00 |
20:20:29.16 |
-76:50:08.6 |
HIP 99551 |
29.96 |
| 2026-03-31 00:00 |
20:20:45.17 |
-76:51:18.9 |
HIP 99551 |
30.44 |
| 2026-03-31 12:00 |
20:21:00.99 |
-76:52:29.6 |
HIP 101099 |
30.85 |
| 2026-04-01 00:00 |
20:21:16.61 |
-76:53:40.7 |
HIP 101099 |
30.36 |
| 2026-04-01 12:00 |
20:21:32.03 |
-76:54:52.1 |
HIP 101099 |
29.95 |
| 2026-04-02 00:00 |
20:21:47.25 |
-76:56:03.9 |
HIP 101099 |
29.63 |
| 2026-04-02 12:00 |
20:22:02.26 |
-76:57:16.1 |
HIP 101099 |
29.39 |
| 2026-04-03 00:00 |
20:22:17.07 |
-76:58:28.7 |
HIP 101099 |
29.24 |
| 2026-04-03 12:00 |
20:22:31.67 |
-76:59:41.6 |
HIP 101099 |
29.18 |
| 2026-04-04 00:00 |
20:22:46.06 |
-77:00:54.8 |
HIP 101099 |
29.21 |
| 2026-04-04 12:00 |
20:23:00.24 |
-77:02:08.4 |
HIP 101099 |
29.32 |
| 2026-04-05 00:00 |
20:23:14.21 |
-77:03:22.4 |
HIP 101099 |
29.53 |
| 2026-04-05 12:00 |
20:23:27.96 |
-77:04:36.7 |
HIP 101291 |
29.02 |
| 2026-04-06 00:00 |
20:23:41.51 |
-77:05:51.3 |
HIP 101291 |
27.97 |
| 2026-04-06 12:00 |
20:23:54.83 |
-77:07:06.3 |
HIP 101291 |
26.97 |
| 2026-04-07 00:00 |
20:24:07.94 |
-77:08:21.6 |
HIP 101291 |
26.03 |
| 2026-04-07 12:00 |
20:24:20.83 |
-77:09:37.2 |
HIP 101291 |
25.15 |
| 2026-04-08 00:00 |
20:24:33.50 |
-77:10:53.2 |
HIP 101291 |
24.34 |
| 2026-04-08 12:00 |
20:24:45.95 |
-77:12:09.5 |
HIP 101291 |
23.61 |
| 2026-04-09 00:00 |
20:24:58.17 |
-77:13:26.1 |
HIP 101291 |
22.96 |
| 2026-04-09 12:00 |
20:25:10.17 |
-77:14:43.0 |
HIP 101291 |
22.40 |
| 2026-04-10 00:00 |
20:25:21.94 |
-77:16:00.3 |
HIP 101291 |
21.93 |
| 2026-04-10 12:00 |
20:25:33.49 |
-77:17:17.8 |
HIP 101291 |
21.57 |
| 2026-04-11 00:00 |
20:25:44.80 |
-77:18:35.7 |
HIP 101291 |
21.31 |
| 2026-04-11 12:00 |
20:25:55.88 |
-77:19:53.8 |
HIP 101291 |
21.17 |
| 2026-04-12 00:00 |
20:26:06.72 |
-77:21:12.3 |
HIP 101291 |
21.14 |
| 2026-04-12 12:00 |
20:26:17.33 |
-77:22:31.0 |
HIP 101129 |
20.70 |
| 2026-04-13 00:00 |
20:26:27.70 |
-77:23:50.0 |
HIP 101129 |
19.30 |
| 2026-04-13 12:00 |
20:26:37.84 |
-77:25:09.3 |
HIP 101129 |
17.91 |
| 2026-04-14 00:00 |
20:26:47.73 |
-77:26:28.9 |
HIP 101129 |
16.53 |
| 2026-04-14 12:00 |
20:26:57.38 |
-77:27:48.7 |
HIP 101129 |
15.16 |
| 2026-04-15 00:00 |
20:27:06.79 |
-77:29:08.8 |
HIP 101129 |
13.82 |
| 2026-04-15 12:00 |
20:27:15.95 |
-77:30:29.2 |
HIP 101129 |
12.50 |
| 2026-04-16 00:00 |
20:27:24.86 |
-77:31:49.8 |
HIP 101129 |
11.21 |