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) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 18:00:45.10 | -13:39:47.9 | HIP 88201 | 7.02 |
| 2026-02-03 12:00 | 18:01:07.60 | -13:39:01.2 | HIP 88201 | 9.73 |
| 2026-02-04 00:00 | 18:01:30.01 | -13:38:13.9 | HIP 88201 | 14.17 |
| 2026-02-04 12:00 | 18:01:52.35 | -13:37:26.1 | HIP 88201 | 19.15 |
| 2026-02-05 00:00 | 18:02:14.60 | -13:36:37.8 | HIP 88201 | 24.34 |
| 2026-02-05 12:00 | 18:02:36.77 | -13:35:48.9 | HIP 88301 | 28.69 |
| 2026-02-06 00:00 | 18:02:58.86 | -13:34:59.4 | HIP 88301 | 30.22 |
| 2026-02-06 12:00 | 18:03:20.86 | -13:34:09.5 | HIP 88301 | 32.57 |
| 2026-02-07 00:00 | 18:03:42.77 | -13:33:18.9 | HIP 88301 | 35.58 |
| 2026-02-07 12:00 | 18:04:04.60 | -13:32:27.9 | HIP 88301 | 39.08 |
| 2026-02-08 00:00 | 18:04:26.35 | -13:31:36.3 | HIP 88748 | 41.75 |
| 2026-02-08 12:00 | 18:04:48.00 | -13:30:44.1 | HIP 88748 | 36.63 |
| 2026-02-09 00:00 | 18:05:09.56 | -13:29:51.5 | HIP 88748 | 31.60 |
| 2026-02-09 12:00 | 18:05:31.04 | -13:28:58.3 | HIP 88748 | 26.69 |
| 2026-02-10 00:00 | 18:05:52.42 | -13:28:04.5 | HIP 88748 | 21.97 |
| 2026-02-10 12:00 | 18:06:13.72 | -13:27:10.3 | HIP 88748 | 17.58 |
| 2026-02-11 00:00 | 18:06:34.91 | -13:26:15.5 | HIP 88748 | 13.82 |
| 2026-02-11 12:00 | 18:06:56.02 | -13:25:20.2 | HIP 88748 | 11.29 |
| 2026-02-12 00:00 | 18:07:17.03 | -13:24:24.4 | HIP 88748 | 10.86 |
| 2026-02-12 12:00 | 18:07:37.94 | -13:23:28.0 | HIP 88748 | 12.73 |
| 2026-02-13 00:00 | 18:07:58.76 | -13:22:31.2 | HIP 88748 | 16.08 |
| 2026-02-13 12:00 | 18:08:19.47 | -13:21:33.8 | HIP 88748 | 20.18 |
| 2026-02-14 00:00 | 18:08:40.09 | -13:20:35.9 | HIP 89013 | 23.36 |
| 2026-02-14 12:00 | 18:09:00.61 | -13:19:37.5 | HIP 89013 | 19.91 |
| 2026-02-15 00:00 | 18:09:21.03 | -13:18:38.6 | HIP 89013 | 17.29 |
| 2026-02-15 12:00 | 18:09:41.34 | -13:17:39.2 | HIP 89013 | 15.93 |
| 2026-02-16 00:00 | 18:10:01.55 | -13:16:39.3 | HIP 89013 | 16.10 |
| 2026-02-16 12:00 | 18:10:21.66 | -13:15:38.9 | HIP 89079 | 17.36 |
| 2026-02-17 00:00 | 18:10:41.66 | -13:14:38.0 | HIP 89079 | 15.23 |
| 2026-02-17 12:00 | 18:11:01.56 | -13:13:36.6 | HIP 89079 | 14.54 |
| 2026-02-18 00:00 | 18:11:21.35 | -13:12:34.8 | HIP 89079 | 15.47 |
| 2026-02-18 12:00 | 18:11:41.03 | -13:11:32.4 | HIP 89079 | 17.74 |
| 2026-02-19 00:00 | 18:12:00.60 | -13:10:29.6 | HIP 89079 | 20.91 |
| 2026-02-19 12:00 | 18:12:20.06 | -13:09:26.3 | HIP 89079 | 24.62 |
| 2026-02-20 00:00 | 18:12:39.41 | -13:08:22.5 | HIP 89079 | 28.65 |
| 2026-02-20 12:00 | 18:12:58.64 | -13:07:18.2 | HIP 89079 | 32.86 |
| 2026-02-21 00:00 | 18:13:17.77 | -13:06:13.5 | HIP 89079 | 37.19 |
| 2026-02-21 12:00 | 18:13:36.78 | -13:05:08.3 | HIP 89441 | 40.47 |
| 2026-02-22 00:00 | 18:13:55.67 | -13:04:02.6 | HIP 89441 | 37.03 |
| 2026-02-22 12:00 | 18:14:14.45 | -13:02:56.5 | HIP 89441 | 33.92 |
| 2026-02-23 00:00 | 18:14:33.11 | -13:01:50.0 | HIP 89441 | 31.20 |
| 2026-02-23 12:00 | 18:14:51.66 | -13:00:42.9 | HIP 89441 | 28.99 |
| 2026-02-24 00:00 | 18:15:10.08 | -12:59:35.5 | HIP 89441 | 27.40 |