240P/NEAT
メタデータ
| 項目 | 値 |
|---|---|
| Designation | 240P/NEAT |
| Type | P |
| Perihelion (tp_cal, UTC) | 2025-12-19T20:48:16.660800Z |
| Orbit solution date (soln_date, UTC) | 2026-05-11T09:03:05Z |
| Obs used | 4046 |
| NEO | - |
| M1 | 11.700 |
| K1 | 7.250 |
| PC | - |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2024-07-08.0000000 |
| e | 0.45033261 |
| q (au) | 2.122538 |
| a (au) | 3.861496 |
| i (deg) | 23.536978 |
| Ω (om, deg) | 74.914423 |
| ω (w, deg) | 352.025889 |
| M (ma, deg) | 291.176388 |
等級
散乱 + 全体線形
$$ M_a = (11.228 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 11.228 |
| n | 2.000 |
| gf | 1.000 |
| gb | -0.995 |
| 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 |
|---|---|---|---|
| 2024-06-13 | 2025-08-01 | +14.9866 | -6.476 |
| 2025-08-01 | 2025-12-19 | +3.7586 | -1.863 |
| 2025-12-19 | 2026-05-09 | +29.5482 | -10.006 |
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 | 06:32:35.39 | +35:52:08.4 | HIP 31193 | 34.53 |
| 2026-05-12 12:00 | 06:33:43.84 | +35:52:34.9 | HIP 31193 | 37.27 |
| 2026-05-13 00:00 | 06:34:52.32 | +35:52:59.5 | HIP 31605 | 25.95 |
| 2026-05-13 12:00 | 06:36:00.83 | +35:53:22.0 | HIP 31605 | 13.94 |
| 2026-05-14 00:00 | 06:37:09.36 | +35:53:42.5 | HIP 31605 | 10.04 |
| 2026-05-14 12:00 | 06:38:17.92 | +35:54:01.0 | HIP 31605 | 19.82 |
| 2026-05-15 00:00 | 06:39:26.49 | +35:54:17.5 | HIP 31953 | 25.34 |
| 2026-05-15 12:00 | 06:40:35.09 | +35:54:32.0 | HIP 32040 | 12.77 |
| 2026-05-16 00:00 | 06:41:43.70 | +35:54:44.5 | HIP 32040 | 1.68 |
| 2026-05-16 12:00 | 06:42:52.33 | +35:54:55.0 | HIP 32040 | 15.13 |
| 2026-05-17 00:00 | 06:44:00.98 | +35:55:03.5 | HIP 32268 | 11.73 |
| 2026-05-17 12:00 | 06:45:09.64 | +35:55:10.1 | HIP 32268 | 16.22 |
| 2026-05-18 00:00 | 06:46:18.31 | +35:55:14.6 | HIP 32364 | 25.82 |
| 2026-05-18 12:00 | 06:47:26.99 | +35:55:17.3 | HIP 32496 | 27.67 |
| 2026-05-19 00:00 | 06:48:35.67 | +35:55:17.9 | HIP 32862 | 32.66 |
| 2026-05-19 12:00 | 06:49:44.37 | +35:55:16.6 | HIP 32862 | 21.66 |
| 2026-05-20 00:00 | 06:50:53.07 | +35:55:13.4 | HIP 32862 | 16.05 |
| 2026-05-20 12:00 | 06:52:01.77 | +35:55:08.2 | HIP 33044 | 14.78 |
| 2026-05-21 00:00 | 06:53:10.47 | +35:55:01.0 | HIP 33044 | 7.86 |
| 2026-05-21 12:00 | 06:54:19.18 | +35:54:51.9 | HIP 33044 | 17.10 |
| 2026-05-22 00:00 | 06:55:27.88 | +35:54:40.9 | HIP 33329 | 16.61 |
| 2026-05-22 12:00 | 06:56:36.58 | +35:54:28.0 | HIP 33329 | 17.73 |
| 2026-05-23 00:00 | 06:57:45.27 | +35:54:13.2 | HIP 33329 | 27.21 |
| 2026-05-23 12:00 | 06:58:53.96 | +35:53:56.4 | HIP 33679 | 27.31 |
| 2026-05-24 00:00 | 07:00:02.63 | +35:53:37.7 | HIP 33821 | 15.04 |
| 2026-05-24 12:00 | 07:01:11.30 | +35:53:17.2 | HIP 33821 | 2.70 |
| 2026-05-25 00:00 | 07:02:19.96 | +35:52:54.7 | HIP 33821 | 13.25 |
| 2026-05-25 12:00 | 07:03:28.61 | +35:52:30.4 | HIP 34136 | 22.96 |
| 2026-05-26 00:00 | 07:04:37.24 | +35:52:04.1 | HIP 34136 | 17.32 |
| 2026-05-26 12:00 | 07:05:45.86 | +35:51:36.0 | HIP 34136 | 21.45 |
| 2026-05-27 00:00 | 07:06:54.46 | +35:51:06.1 | HIP 34411 | 13.85 |
| 2026-05-27 12:00 | 07:08:03.04 | +35:50:34.2 | HIP 34411 | 1.13 |
| 2026-05-28 00:00 | 07:09:11.61 | +35:50:00.5 | HIP 34411 | 14.05 |
| 2026-05-28 12:00 | 07:10:20.16 | +35:49:24.9 | HIP 34411 | 27.94 |
| 2026-05-29 00:00 | 07:11:28.68 | +35:48:47.5 | HIP 34806 | 21.37 |
| 2026-05-29 12:00 | 07:12:37.18 | +35:48:08.3 | HIP 34916 | 12.26 |
| 2026-05-30 00:00 | 07:13:45.66 | +35:47:27.2 | HIP 34916 | 7.15 |
| 2026-05-30 12:00 | 07:14:54.12 | +35:46:44.3 | HIP 34969 | 16.67 |
| 2026-05-31 00:00 | 07:16:02.55 | +35:45:59.5 | HIP 35282 | 20.91 |
| 2026-05-31 12:00 | 07:17:10.95 | +35:45:13.0 | HIP 35282 | 14.73 |
| 2026-06-01 00:00 | 07:18:19.33 | +35:44:24.6 | HIP 35282 | 19.57 |
| 2026-06-01 12:00 | 07:19:27.68 | +35:43:34.4 | HIP 35282 | 30.57 |
| 2026-06-02 00:00 | 07:20:36.00 | +35:42:42.5 | HIP 35755 | 25.91 |