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) |
|---|---|---|---|---|
| 2026-03-26 00:00 | 17:08:11.30 | -30:22:09.3 | HIP 83806 | 8.08 |
| 2026-03-26 12:00 | 17:08:11.98 | -30:22:41.7 | HIP 83896 | 7.82 |
| 2026-03-27 00:00 | 17:08:12.46 | -30:23:13.9 | HIP 83896 | 7.63 |
| 2026-03-27 12:00 | 17:08:12.73 | -30:23:45.8 | HIP 83896 | 7.52 |
| 2026-03-28 00:00 | 17:08:12.79 | -30:24:17.5 | HIP 83896 | 7.49 |
| 2026-03-28 12:00 | 17:08:12.64 | -30:24:48.9 | HIP 83896 | 7.55 |
| 2026-03-29 00:00 | 17:08:12.28 | -30:25:20.1 | HIP 83896 | 7.69 |
| 2026-03-29 12:00 | 17:08:11.71 | -30:25:51.0 | HIP 83896 | 7.90 |
| 2026-03-30 00:00 | 17:08:10.92 | -30:26:21.7 | HIP 83896 | 8.18 |
| 2026-03-30 12:00 | 17:08:09.93 | -30:26:52.1 | HIP 83896 | 8.53 |
| 2026-03-31 00:00 | 17:08:08.72 | -30:27:22.3 | HIP 83896 | 8.94 |
| 2026-03-31 12:00 | 17:08:07.31 | -30:27:52.2 | HIP 83896 | 9.41 |
| 2026-04-01 00:00 | 17:08:05.68 | -30:28:21.8 | HIP 83896 | 9.93 |
| 2026-04-01 12:00 | 17:08:03.83 | -30:28:51.1 | HIP 83798 | 9.35 |
| 2026-04-02 00:00 | 17:08:01.77 | -30:29:20.1 | HIP 83798 | 8.69 |
| 2026-04-02 12:00 | 17:07:59.50 | -30:29:48.8 | HIP 83798 | 8.01 |
| 2026-04-03 00:00 | 17:07:57.02 | -30:30:17.3 | HIP 83798 | 7.30 |
| 2026-04-03 12:00 | 17:07:54.31 | -30:30:45.5 | HIP 83798 | 6.56 |
| 2026-04-04 00:00 | 17:07:51.40 | -30:31:13.3 | HIP 83798 | 5.80 |
| 2026-04-04 12:00 | 17:07:48.27 | -30:31:40.8 | HIP 83798 | 5.01 |
| 2026-04-05 00:00 | 17:07:44.92 | -30:32:08.1 | HIP 83798 | 4.22 |
| 2026-04-05 12:00 | 17:07:41.35 | -30:32:35.0 | HIP 83798 | 3.44 |
| 2026-04-06 00:00 | 17:07:37.57 | -30:33:01.6 | HIP 83798 | 2.72 |
| 2026-04-06 12:00 | 17:07:33.58 | -30:33:27.8 | HIP 83798 | 2.16 |
| 2026-04-07 00:00 | 17:07:29.36 | -30:33:53.7 | HIP 83798 | 1.99 |
| 2026-04-07 12:00 | 17:07:24.93 | -30:34:19.3 | HIP 83798 | 2.33 |
| 2026-04-08 00:00 | 17:07:20.28 | -30:34:44.5 | HIP 83798 | 3.06 |
| 2026-04-08 12:00 | 17:07:15.41 | -30:35:09.4 | HIP 83798 | 4.01 |
| 2026-04-09 00:00 | 17:07:10.33 | -30:35:33.9 | HIP 83798 | 5.07 |
| 2026-04-09 12:00 | 17:07:05.03 | -30:35:58.1 | HIP 83798 | 6.22 |
| 2026-04-10 00:00 | 17:06:59.50 | -30:36:21.9 | HIP 83798 | 7.44 |
| 2026-04-10 12:00 | 17:06:53.76 | -30:36:45.3 | HIP 83798 | 8.71 |
| 2026-04-11 00:00 | 17:06:47.80 | -30:37:08.3 | HIP 83703 | 8.45 |
| 2026-04-11 12:00 | 17:06:41.63 | -30:37:31.0 | HIP 83703 | 7.43 |
| 2026-04-12 00:00 | 17:06:35.23 | -30:37:53.2 | HIP 83703 | 6.53 |
| 2026-04-12 12:00 | 17:06:28.62 | -30:38:15.1 | HIP 83703 | 5.84 |
| 2026-04-13 00:00 | 17:06:21.79 | -30:38:36.5 | HIP 83703 | 5.48 |
| 2026-04-13 12:00 | 17:06:14.74 | -30:38:57.6 | HIP 83703 | 5.55 |
| 2026-04-14 00:00 | 17:06:07.47 | -30:39:18.2 | HIP 83703 | 6.07 |
| 2026-04-14 12:00 | 17:05:59.98 | -30:39:38.4 | HIP 83703 | 6.97 |
| 2026-04-15 00:00 | 17:05:52.28 | -30:39:58.1 | HIP 83703 | 8.15 |
| 2026-04-15 12:00 | 17:05:44.35 | -30:40:17.5 | HIP 83703 | 9.53 |
| 2026-04-16 00:00 | 17:05:36.22 | -30:40:36.4 | HIP 83703 | 11.06 |