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
$$ M_a = (14.628 + 2.269\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 14.628 |
| n | 2.269 |
| gf | 0.952 |
| gb | -0.851 |
| k | 0.999 |
| δ90 | 8.671 |
| 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 | +2.5717 | -0.611 |
| 2021-11-02 | 2022-03-07 | -4.0897 | +1.124 |
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 | 18:30:15.83 | -09:23:37.5 | HIP 90633 | 11.88 |
| 2026-05-12 12:00 | 18:30:06.82 | -09:22:20.3 | HIP 90633 | 9.31 |
| 2026-05-13 00:00 | 18:29:57.61 | -09:21:03.5 | HIP 90633 | 6.71 |
| 2026-05-13 12:00 | 18:29:48.21 | -09:19:47.1 | HIP 90633 | 4.08 |
| 2026-05-14 00:00 | 18:29:38.62 | -09:18:31.3 | HIP 90633 | 1.49 |
| 2026-05-14 12:00 | 18:29:28.83 | -09:17:15.9 | HIP 90633 | 1.53 |
| 2026-05-15 00:00 | 18:29:18.85 | -09:16:01.0 | HIP 90633 | 4.20 |
| 2026-05-15 12:00 | 18:29:08.68 | -09:14:46.6 | HIP 90633 | 6.98 |
| 2026-05-16 00:00 | 18:28:58.32 | -09:13:32.7 | HIP 90633 | 9.81 |
| 2026-05-16 12:00 | 18:28:47.77 | -09:12:19.3 | HIP 90633 | 12.69 |
| 2026-05-17 00:00 | 18:28:37.04 | -09:11:06.4 | HIP 90633 | 15.60 |
| 2026-05-17 12:00 | 18:28:26.12 | -09:09:54.1 | HIP 90633 | 18.55 |
| 2026-05-18 00:00 | 18:28:15.01 | -09:08:42.3 | HIP 90633 | 21.54 |
| 2026-05-18 12:00 | 18:28:03.72 | -09:07:31.1 | HIP 90436 | 20.09 |
| 2026-05-19 00:00 | 18:27:52.25 | -09:06:20.4 | HIP 90436 | 17.35 |
| 2026-05-19 12:00 | 18:27:40.60 | -09:05:10.3 | HIP 90436 | 14.73 |
| 2026-05-20 00:00 | 18:27:28.76 | -09:04:00.7 | HIP 90436 | 12.33 |
| 2026-05-20 12:00 | 18:27:16.76 | -09:02:51.7 | HIP 90436 | 10.34 |
| 2026-05-21 00:00 | 18:27:04.57 | -09:01:43.3 | HIP 90436 | 9.06 |
| 2026-05-21 12:00 | 18:26:52.21 | -09:00:35.5 | HIP 90436 | 8.87 |
| 2026-05-22 00:00 | 18:26:39.68 | -08:59:28.3 | HIP 90436 | 9.85 |
| 2026-05-22 12:00 | 18:26:26.98 | -08:58:21.7 | HIP 90436 | 11.75 |
| 2026-05-23 00:00 | 18:26:14.10 | -08:57:15.7 | HIP 90436 | 14.23 |
| 2026-05-23 12:00 | 18:26:01.06 | -08:56:10.3 | HIP 90436 | 17.06 |
| 2026-05-24 00:00 | 18:25:47.85 | -08:55:05.5 | HIP 90436 | 20.11 |
| 2026-05-24 12:00 | 18:25:34.48 | -08:54:01.4 | HIP 90382 | 23.22 |
| 2026-05-25 00:00 | 18:25:20.95 | -08:52:57.9 | HIP 90135 | 25.23 |
| 2026-05-25 12:00 | 18:25:07.25 | -08:51:55.0 | HIP 90135 | 22.06 |
| 2026-05-26 00:00 | 18:24:53.40 | -08:50:52.8 | HIP 90135 | 18.96 |
| 2026-05-26 12:00 | 18:24:39.39 | -08:49:51.3 | HIP 90135 | 16.03 |
| 2026-05-27 00:00 | 18:24:25.22 | -08:48:50.4 | HIP 90135 | 13.40 |
| 2026-05-27 12:00 | 18:24:10.89 | -08:47:50.1 | HIP 90135 | 11.30 |
| 2026-05-28 00:00 | 18:23:56.42 | -08:46:50.6 | HIP 90135 | 10.12 |
| 2026-05-28 12:00 | 18:23:41.79 | -08:45:51.7 | HIP 90135 | 10.22 |
| 2026-05-29 00:00 | 18:23:27.02 | -08:44:53.5 | HIP 90135 | 11.60 |
| 2026-05-29 12:00 | 18:23:12.10 | -08:43:56.0 | HIP 90135 | 13.90 |
| 2026-05-30 00:00 | 18:22:57.03 | -08:42:59.2 | HIP 90135 | 16.78 |
| 2026-05-30 12:00 | 18:22:41.82 | -08:42:03.1 | HIP 90135 | 20.00 |
| 2026-05-31 00:00 | 18:22:26.47 | -08:41:07.7 | HIP 90135 | 23.44 |
| 2026-05-31 12:00 | 18:22:10.98 | -08:40:13.0 | HIP 89973 | 25.74 |
| 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 |