399P/PANSTARRS
メタデータ
| 項目 | 値 |
|---|---|
| Designation | 399P/PANSTARRS |
| Type | P |
| Perihelion (tp_cal, UTC) | 2021-05-26T11:27:46.031040Z |
| Orbit solution date (soln_date, UTC) | 2023-12-06T01:15:28Z |
| Obs used | 407 |
| NEO | - |
| M1 | 15.900 |
| 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) | 2017-11-18.0000000 |
| e | 0.44196144 |
| q (au) | 2.126918 |
| a (au) | 3.811418 |
| i (deg) | 13.345891 |
| Ω (om, deg) | 207.564221 |
| ω (w, deg) | 213.321157 |
| M (ma, deg) | 189.729777 |
等級
散乱 + 全体線形
$$ M_a = (14.631 + 2.270\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 14.631 |
| n | 2.270 |
| gf | 0.946 |
| gb | -0.851 |
| k | 0.999 |
| δ90 | 8.448 |
| 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 |
|---|---|---|---|
| 2020-07-30 | 2021-02-17 | +2.5704 | -0.611 |
| 2021-11-02 | 2022-03-07 | -4.0919 | +1.125 |
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) |
|---|---|---|---|---|
| 2026-06-01 00:00 | 18:21:55.35 | -08:39:19.1 | HIP 89973 | 23.48 |
| 2026-06-01 12:00 | 18:21:39.59 | -08:38:25.8 | HIP 89973 | 21.72 |
| 2026-06-02 00:00 | 18:21:23.70 | -08:37:33.3 | HIP 89973 | 20.60 |
| 2026-06-02 12:00 | 18:21:07.67 | -08:36:41.6 | HIP 89973 | 20.27 |
| 2026-06-03 00:00 | 18:20:51.52 | -08:35:50.6 | HIP 89973 | 20.76 |
| 2026-06-03 12:00 | 18:20:35.24 | -08:35:00.3 | HIP 89973 | 22.04 |
| 2026-06-04 00:00 | 18:20:18.83 | -08:34:10.8 | HIP 89973 | 23.99 |
| 2026-06-04 12:00 | 18:20:02.30 | -08:33:22.1 | HIP 89973 | 26.49 |
| 2026-06-05 00:00 | 18:19:45.65 | -08:32:34.1 | HIP 89686 | 24.63 |
| 2026-06-05 12:00 | 18:19:28.89 | -08:31:46.9 | HIP 89686 | 20.83 |
| 2026-06-06 00:00 | 18:19:12.01 | -08:31:00.5 | HIP 89686 | 17.20 |
| 2026-06-06 12:00 | 18:18:55.01 | -08:30:14.9 | HIP 89686 | 13.88 |
| 2026-06-07 00:00 | 18:18:37.90 | -08:29:30.1 | HIP 89686 | 11.20 |
| 2026-06-07 12:00 | 18:18:20.69 | -08:28:46.0 | HIP 89686 | 9.73 |
| 2026-06-08 00:00 | 18:18:03.37 | -08:28:02.8 | HIP 89686 | 10.05 |
| 2026-06-08 12:00 | 18:17:45.95 | -08:27:20.4 | HIP 89686 | 12.04 |
| 2026-06-09 00:00 | 18:17:28.42 | -08:26:38.8 | HIP 89686 | 15.08 |
| 2026-06-09 12:00 | 18:17:10.80 | -08:25:58.0 | HIP 89686 | 18.67 |
| 2026-06-10 00:00 | 18:16:53.08 | -08:25:18.1 | HIP 89686 | 22.57 |
| 2026-06-10 12:00 | 18:16:35.26 | -08:24:39.0 | HIP 89686 | 26.64 |
| 2026-06-11 00:00 | 18:16:17.36 | -08:24:00.7 | HIP 89381 | 28.06 |
| 2026-06-11 12:00 | 18:15:59.37 | -08:23:23.3 | HIP 89381 | 23.59 |
| 2026-06-12 00:00 | 18:15:41.29 | -08:22:46.7 | HIP 89381 | 19.10 |
| 2026-06-12 12:00 | 18:15:23.13 | -08:22:11.0 | HIP 89381 | 14.61 |
| 2026-06-13 00:00 | 18:15:04.90 | -08:21:36.1 | HIP 89381 | 10.13 |
| 2026-06-13 12:00 | 18:14:46.58 | -08:21:02.1 | HIP 89381 | 5.74 |
| 2026-06-14 00:00 | 18:14:28.19 | -08:20:29.0 | HIP 89381 | 2.21 |
| 2026-06-14 12:00 | 18:14:09.74 | -08:19:56.7 | HIP 89381 | 4.34 |
| 2026-06-15 00:00 | 18:13:51.21 | -08:19:25.3 | HIP 89381 | 8.67 |
| 2026-06-15 12:00 | 18:13:32.62 | -08:18:54.8 | HIP 89381 | 13.21 |
| 2026-06-16 00:00 | 18:13:13.97 | -08:18:25.2 | HIP 89381 | 17.80 |
| 2026-06-16 12:00 | 18:12:55.26 | -08:17:56.5 | HIP 89381 | 22.43 |
| 2026-06-17 00:00 | 18:12:36.50 | -08:17:28.6 | HIP 89381 | 27.07 |
| 2026-06-17 12:00 | 18:12:17.69 | -08:17:01.6 | HIP 89181 | 27.13 |
| 2026-06-18 00:00 | 18:11:58.82 | -08:16:35.6 | HIP 89181 | 27.27 |
| 2026-06-18 12:00 | 18:11:39.92 | -08:16:10.4 | HIP 89181 | 28.19 |
| 2026-06-19 00:00 | 18:11:20.97 | -08:15:46.1 | HIP 89181 | 29.81 |
| 2026-06-19 12:00 | 18:11:01.98 | -08:15:22.8 | HIP 88996 | 26.82 |
| 2026-06-20 00:00 | 18:10:42.95 | -08:15:00.3 | HIP 88996 | 23.75 |
| 2026-06-20 12:00 | 18:10:23.90 | -08:14:38.7 | HIP 88996 | 21.30 |
| 2026-06-21 00:00 | 18:10:04.81 | -08:14:18.0 | HIP 88996 | 19.72 |
| 2026-06-21 12:00 | 18:09:45.69 | -08:13:58.3 | HIP 88996 | 19.22 |
| 2026-06-22 00:00 | 18:09:26.56 | -08:13:39.4 | HIP 88996 | 19.89 |