P/2020 G1 (Pimentel)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | P/2020 G1 (Pimentel) |
| Type | P |
| Perihelion (tp_cal, UTC) | 2020-03-17T09:47:11.889600Z |
| Orbit solution date (soln_date, UTC) | 2021-04-15T23:34:05Z |
| Obs used | 490 |
| NEO | Yes |
| M1 | 17.400 |
| K1 | 4.500 |
| PC | 0.030 |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2020-05-04.0000000 |
| e | 0.85961155 |
| q (au) | 0.505764 |
| a (au) | 3.602603 |
| i (deg) | 18.472732 |
| Ω (om, deg) | 240.105496 |
| ω (w, deg) | 207.637592 |
| M (ma, deg) | 6.859863 |
等級
散乱 + 全体線形
$$ M_a = (17.331 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 17.331 |
| n | 2.000 |
| gf | 0.800 |
| gb | -0.696 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) | 終了日 (UTC) | a | b |
|---|---|---|---|
| 2020-04-13 | 2020-04-29 | +4.8811 | +0.451 |
| 2020-04-29 | 2020-05-31 | -5.2578 | +0.285 |
| 2020-05-31 | 2020-07-19 | +18.1081 | -3.892 |
log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)
ファインディングチャート
天体暦
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 19:46:36.03 | -08:50:47.1 | HIP 97173 | 26.28 |
| 2026-02-03 12:00 | 19:47:04.92 | -08:48:57.1 | HIP 97173 | 32.05 |
| 2026-02-04 00:00 | 19:47:33.80 | -08:47:06.4 | HIP 97519 | 26.21 |
| 2026-02-04 12:00 | 19:48:02.68 | -08:45:14.7 | HIP 97519 | 20.42 |
| 2026-02-05 00:00 | 19:48:31.55 | -08:43:22.2 | HIP 97519 | 16.02 |
| 2026-02-05 12:00 | 19:49:00.42 | -08:41:28.9 | HIP 97519 | 14.32 |
| 2026-02-06 00:00 | 19:49:29.27 | -08:39:34.8 | HIP 97600 | 11.94 |
| 2026-02-06 12:00 | 19:49:58.12 | -08:37:39.8 | HIP 97600 | 4.57 |
| 2026-02-07 00:00 | 19:50:26.95 | -08:35:44.0 | HIP 97600 | 2.86 |
| 2026-02-07 12:00 | 19:50:55.77 | -08:33:47.3 | HIP 97600 | 10.23 |
| 2026-02-08 00:00 | 19:51:24.58 | -08:31:49.8 | HIP 97600 | 17.61 |
| 2026-02-08 12:00 | 19:51:53.38 | -08:29:51.5 | HIP 97600 | 25.00 |
| 2026-02-09 00:00 | 19:52:22.17 | -08:27:52.3 | HIP 97928 | 27.05 |
| 2026-02-09 12:00 | 19:52:50.94 | -08:25:52.3 | HIP 97928 | 20.96 |
| 2026-02-10 00:00 | 19:53:19.70 | -08:23:51.4 | HIP 97928 | 16.01 |
| 2026-02-10 12:00 | 19:53:48.44 | -08:21:49.8 | HIP 97928 | 13.54 |
| 2026-02-11 00:00 | 19:54:17.16 | -08:19:47.3 | HIP 97967 | 7.60 |
| 2026-02-11 12:00 | 19:54:45.87 | -08:17:43.9 | HIP 97967 | 4.01 |
| 2026-02-12 00:00 | 19:55:14.56 | -08:15:39.7 | HIP 97967 | 9.14 |
| 2026-02-12 12:00 | 19:55:43.23 | -08:13:34.7 | HIP 97967 | 16.14 |
| 2026-02-13 00:00 | 19:56:11.88 | -08:11:28.9 | HIP 97967 | 23.37 |
| 2026-02-13 12:00 | 19:56:40.51 | -08:09:22.3 | HIP 98029 | 30.12 |
| 2026-02-14 00:00 | 19:57:09.12 | -08:07:14.8 | HIP 98387 | 33.57 |
| 2026-02-14 12:00 | 19:57:37.70 | -08:05:06.5 | HIP 98387 | 26.44 |
| 2026-02-15 00:00 | 19:58:06.27 | -08:02:57.3 | HIP 98387 | 19.52 |
| 2026-02-15 12:00 | 19:58:34.81 | -08:00:47.4 | HIP 98387 | 13.13 |
| 2026-02-16 00:00 | 19:59:03.32 | -07:58:36.6 | HIP 98387 | 8.55 |
| 2026-02-16 12:00 | 19:59:31.81 | -07:56:25.0 | HIP 98387 | 9.13 |
| 2026-02-17 00:00 | 20:00:00.27 | -07:54:12.6 | HIP 98387 | 14.24 |
| 2026-02-17 12:00 | 20:00:28.71 | -07:51:59.4 | HIP 98387 | 20.77 |
| 2026-02-18 00:00 | 20:00:57.12 | -07:49:45.3 | HIP 98387 | 27.73 |
| 2026-02-18 12:00 | 20:01:25.50 | -07:47:30.5 | HIP 98720 | 24.98 |
| 2026-02-19 00:00 | 20:01:53.85 | -07:45:14.8 | HIP 98720 | 17.64 |
| 2026-02-19 12:00 | 20:02:22.16 | -07:42:58.4 | HIP 98720 | 10.35 |
| 2026-02-20 00:00 | 20:02:50.45 | -07:40:41.1 | HIP 98720 | 3.48 |
| 2026-02-20 12:00 | 20:03:18.70 | -07:38:23.0 | HIP 98720 | 5.07 |
| 2026-02-21 00:00 | 20:03:46.93 | -07:36:04.1 | HIP 98809 | 8.66 |
| 2026-02-21 12:00 | 20:04:15.11 | -07:33:44.5 | HIP 98809 | 6.56 |
| 2026-02-22 00:00 | 20:04:43.26 | -07:31:24.0 | HIP 98809 | 10.92 |
| 2026-02-22 12:00 | 20:05:11.38 | -07:29:02.7 | HIP 98809 | 17.42 |
| 2026-02-23 00:00 | 20:05:39.46 | -07:26:40.7 | HIP 98809 | 24.40 |
| 2026-02-23 12:00 | 20:06:07.51 | -07:24:17.8 | HIP 98809 | 31.55 |
| 2026-02-24 00:00 | 20:06:35.51 | -07:21:54.2 | HIP 99242 | 37.78 |