64P/Swift-Gehrels
メタデータ
| 項目 | 値 |
|---|---|
| Designation | 64P/Swift-Gehrels |
| Type | P |
| Perihelion (tp_cal, UTC) | 2018-11-03T21:53:15.495360Z |
| Orbit solution date (soln_date, UTC) | 2023-12-21T08:26:18Z |
| Obs used | 3436 |
| NEO | - |
| M1 | 14.500 |
| K1 | 6.000 |
| PC | - |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2017-12-09.0000000 |
| e | 0.68732017 |
| q (au) | 1.393350 |
| a (au) | 4.456157 |
| i (deg) | 8.948393 |
| Ω (om, deg) | 300.000979 |
| ω (w, deg) | 97.144197 |
| M (ma, deg) | 325.433022 |
等級
散乱 + 全体線形
$$ M_a = (12.980 + 2.682\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 12.980 |
| n | 2.682 |
| gf | 1.000 |
| gb | -0.502 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) | 終了日 (UTC) | a | b |
|---|---|---|---|
| 2018-05-25 | 2018-08-18 | +18.4191 | -3.252 |
| 2018-08-18 | 2018-11-03 | +26.1368 | -4.376 |
| 2018-11-03 | 2019-05-06 | +1.5754 | -1.769 |
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) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 16:53:56.70 | -30:44:08.1 | HIP 82717 | 6.59 |
| 2026-05-12 12:00 | 16:53:38.57 | -30:43:54.4 | HIP 82717 | 10.44 |
| 2026-05-13 00:00 | 16:53:20.30 | -30:43:40.0 | HIP 82570 | 8.10 |
| 2026-05-13 12:00 | 16:53:01.89 | -30:43:24.8 | HIP 82570 | 4.26 |
| 2026-05-14 00:00 | 16:52:43.34 | -30:43:08.8 | HIP 82570 | 1.44 |
| 2026-05-14 12:00 | 16:52:24.65 | -30:42:52.0 | HIP 82570 | 4.26 |
| 2026-05-15 00:00 | 16:52:05.82 | -30:42:34.4 | HIP 82570 | 8.19 |
| 2026-05-15 12:00 | 16:51:46.87 | -30:42:16.1 | HIP 82467 | 7.84 |
| 2026-05-16 00:00 | 16:51:27.78 | -30:41:57.0 | HIP 82467 | 3.85 |
| 2026-05-16 12:00 | 16:51:08.58 | -30:41:37.1 | HIP 82467 | 1.42 |
| 2026-05-17 00:00 | 16:50:49.24 | -30:41:16.4 | HIP 82467 | 4.87 |
| 2026-05-17 12:00 | 16:50:29.79 | -30:40:54.9 | HIP 82467 | 8.98 |
| 2026-05-18 00:00 | 16:50:10.22 | -30:40:32.6 | HIP 82467 | 13.18 |
| 2026-05-18 12:00 | 16:49:50.54 | -30:40:09.5 | HIP 82317 | 10.79 |
| 2026-05-19 00:00 | 16:49:30.74 | -30:39:45.6 | HIP 82317 | 8.25 |
| 2026-05-19 12:00 | 16:49:10.84 | -30:39:20.9 | HIP 82317 | 7.51 |
| 2026-05-20 00:00 | 16:48:50.83 | -30:38:55.3 | HIP 82317 | 9.05 |
| 2026-05-20 12:00 | 16:48:30.72 | -30:38:29.0 | HIP 82317 | 12.06 |
| 2026-05-21 00:00 | 16:48:10.51 | -30:38:01.9 | HIP 82317 | 15.74 |
| 2026-05-21 12:00 | 16:47:50.21 | -30:37:34.0 | HIP 82132 | 13.99 |
| 2026-05-22 00:00 | 16:47:29.81 | -30:37:05.3 | HIP 82132 | 9.64 |
| 2026-05-22 12:00 | 16:47:09.33 | -30:36:35.7 | HIP 82132 | 5.37 |
| 2026-05-23 00:00 | 16:46:48.75 | -30:36:05.4 | HIP 82132 | 2.02 |
| 2026-05-23 12:00 | 16:46:28.09 | -30:35:34.2 | HIP 82132 | 4.39 |
| 2026-05-24 00:00 | 16:46:07.36 | -30:35:02.3 | HIP 82132 | 8.65 |
| 2026-05-24 12:00 | 16:45:46.54 | -30:34:29.5 | HIP 82132 | 13.09 |
| 2026-05-25 00:00 | 16:45:25.65 | -30:33:55.9 | HIP 81985 | 12.41 |
| 2026-05-25 12:00 | 16:45:04.69 | -30:33:21.6 | HIP 81985 | 9.98 |
| 2026-05-26 00:00 | 16:44:43.66 | -30:32:46.4 | HIP 81985 | 9.29 |
| 2026-05-26 12:00 | 16:44:22.57 | -30:32:10.4 | HIP 81985 | 10.71 |
| 2026-05-27 00:00 | 16:44:01.41 | -30:31:33.6 | HIP 81985 | 13.61 |
| 2026-05-27 12:00 | 16:43:40.20 | -30:30:56.1 | HIP 81985 | 17.28 |
| 2026-05-28 00:00 | 16:43:18.93 | -30:30:17.7 | HIP 81764 | 15.88 |
| 2026-05-28 12:00 | 16:42:57.60 | -30:29:38.5 | HIP 81764 | 11.42 |
| 2026-05-29 00:00 | 16:42:36.23 | -30:28:58.6 | HIP 81764 | 7.18 |
| 2026-05-29 12:00 | 16:42:14.81 | -30:28:17.8 | HIP 81764 | 3.99 |
| 2026-05-30 00:00 | 16:41:53.35 | -30:27:36.3 | HIP 81764 | 4.90 |
| 2026-05-30 12:00 | 16:41:31.85 | -30:26:54.0 | HIP 81764 | 8.72 |
| 2026-05-31 00:00 | 16:41:10.31 | -30:26:10.9 | HIP 81764 | 13.13 |
| 2026-05-31 12:00 | 16:40:48.74 | -30:25:27.0 | HIP 81764 | 17.69 |
| 2026-06-01 00:00 | 16:40:27.13 | -30:24:42.3 | HIP 81552 | 14.66 |
| 2026-06-01 12:00 | 16:40:05.50 | -30:23:56.9 | HIP 81552 | 10.42 |
| 2026-06-02 00:00 | 16:39:43.85 | -30:23:10.8 | HIP 81552 | 6.85 |