240P/NEAT
メタデータ
| 項目 | 値 |
|---|---|
| Designation | 240P/NEAT |
| Type | P |
| Perihelion (tp_cal, UTC) | 2025-12-19T20:28:25.032000Z |
| Orbit solution date (soln_date, UTC) | 2026-01-13T17:43:09Z |
| Obs used | 3083 |
| NEO | - |
| M1 | 10.900 |
| K1 | 8.750 |
| PC | 0.030 |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2024-01-03.0000000 |
| e | 0.45024060 |
| q (au) | 2.123403 |
| a (au) | 3.862423 |
| i (deg) | 23.536267 |
| Ω (om, deg) | 74.912893 |
| ω (w, deg) | 351.996616 |
| M (ma, deg) | 266.922544 |
等級
散乱 + 全体線形
$$ M_a = (9.416 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 9.416 |
| n | 6.000 |
| gf | 1.000 |
| gb | -0.705 |
| k | 0.800 |
| 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 |
|---|---|---|---|
| 2024-06-13 | 2025-08-02 | +10.3009 | -4.380 |
| 2025-08-02 | 2025-12-19 | -9.2671 | +3.334 |
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 | 03:33:21.25 | +23:56:53.5 | HIP 16529 | 16.94 |
| 2026-02-03 12:00 | 03:33:50.37 | +24:03:18.0 | HIP 16639 | 17.80 |
| 2026-02-04 00:00 | 03:34:19.90 | +24:09:41.1 | HIP 16639 | 11.36 |
| 2026-02-04 12:00 | 03:34:49.83 | +24:16:02.7 | HIP 16639 | 10.74 |
| 2026-02-05 00:00 | 03:35:20.17 | +24:22:23.0 | HIP 16664 | 13.37 |
| 2026-02-05 12:00 | 03:35:50.90 | +24:28:41.9 | HIP 16664 | 19.20 |
| 2026-02-06 00:00 | 03:36:22.04 | +24:34:59.4 | HIP 16664 | 27.20 |
| 2026-02-06 12:00 | 03:36:53.57 | +24:41:15.5 | HIP 16996 | 23.82 |
| 2026-02-07 00:00 | 03:37:25.49 | +24:47:30.2 | HIP 16996 | 19.64 |
| 2026-02-07 12:00 | 03:37:57.80 | +24:53:43.4 | HIP 17034 | 19.44 |
| 2026-02-08 00:00 | 03:38:30.50 | +24:59:55.3 | HIP 17037 | 12.64 |
| 2026-02-08 12:00 | 03:39:03.59 | +25:06:05.7 | HIP 17037 | 3.42 |
| 2026-02-09 00:00 | 03:39:37.06 | +25:12:14.7 | HIP 17037 | 7.28 |
| 2026-02-09 12:00 | 03:40:10.91 | +25:18:22.3 | HIP 17181 | 8.12 |
| 2026-02-10 00:00 | 03:40:45.14 | +25:24:28.5 | HIP 17181 | 4.71 |
| 2026-02-10 12:00 | 03:41:19.75 | +25:30:33.2 | HIP 17245 | 7.58 |
| 2026-02-11 00:00 | 03:41:54.73 | +25:36:36.5 | HIP 17245 | 4.22 |
| 2026-02-11 12:00 | 03:42:30.08 | +25:42:38.3 | HIP 17245 | 13.33 |
| 2026-02-12 00:00 | 03:43:05.80 | +25:48:38.7 | HIP 17245 | 23.23 |
| 2026-02-12 12:00 | 03:43:41.89 | +25:54:37.7 | HIP 17407 | 28.26 |
| 2026-02-13 00:00 | 03:44:18.35 | +26:00:35.2 | HIP 17525 | 20.33 |
| 2026-02-13 12:00 | 03:44:55.16 | +26:06:31.2 | HIP 17525 | 11.42 |
| 2026-02-14 00:00 | 03:45:32.34 | +26:12:25.8 | HIP 17525 | 7.46 |
| 2026-02-14 12:00 | 03:46:09.87 | +26:18:18.9 | HIP 17609 | 5.81 |
| 2026-02-15 00:00 | 03:46:47.76 | +26:24:10.5 | HIP 17609 | 12.84 |
| 2026-02-15 12:00 | 03:47:26.00 | +26:30:00.7 | HIP 17774 | 12.99 |
| 2026-02-16 00:00 | 03:48:04.60 | +26:35:49.4 | HIP 17774 | 3.24 |
| 2026-02-16 12:00 | 03:48:43.54 | +26:41:36.6 | HIP 17774 | 8.33 |
| 2026-02-17 00:00 | 03:49:22.82 | +26:47:22.3 | HIP 17774 | 18.65 |
| 2026-02-17 12:00 | 03:50:02.46 | +26:53:06.5 | HIP 17774 | 29.14 |
| 2026-02-18 00:00 | 03:50:42.43 | +26:58:49.2 | HIP 17924 | 29.23 |
| 2026-02-18 12:00 | 03:51:22.74 | +27:04:30.4 | HIP 17924 | 28.79 |
| 2026-02-19 00:00 | 03:52:03.39 | +27:10:10.1 | HIP 18230 | 28.92 |
| 2026-02-19 12:00 | 03:52:44.37 | +27:15:48.3 | HIP 18230 | 26.49 |
| 2026-02-20 00:00 | 03:53:25.68 | +27:21:24.9 | HIP 18230 | 28.20 |
| 2026-02-20 12:00 | 03:54:07.32 | +27:27:00.0 | HIP 18330 | 26.65 |
| 2026-02-21 00:00 | 03:54:49.29 | +27:32:33.6 | HIP 18330 | 28.95 |
| 2026-02-21 12:00 | 03:55:31.58 | +27:38:05.7 | HIP 18386 | 32.67 |
| 2026-02-22 00:00 | 03:56:14.19 | +27:43:36.2 | HIP 18386 | 27.55 |
| 2026-02-22 12:00 | 03:56:57.12 | +27:49:05.1 | HIP 18386 | 26.28 |
| 2026-02-23 00:00 | 03:57:40.36 | +27:54:32.5 | HIP 18386 | 29.44 |
| 2026-02-23 12:00 | 03:58:23.92 | +27:59:58.3 | HIP 18386 | 35.89 |
| 2026-02-24 00:00 | 03:59:07.79 | +28:05:22.6 | HIP 18781 | 39.20 |