240P/NEAT
メタデータ
| 項目 | 値 |
|---|---|
| Designation | 240P/NEAT |
| Type | P |
| Perihelion (tp_cal, UTC) | 2025-12-19T20:38:06.192960Z |
| Orbit solution date (soln_date, UTC) | 2026-03-31T13:32:59Z |
| Obs used | 3830 |
| NEO | - |
| M1 | 11.600 |
| K1 | 7.500 |
| PC | - |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2024-06-10.0000000 |
| e | 0.45032534 |
| q (au) | 2.122654 |
| a (au) | 3.861655 |
| i (deg) | 23.536971 |
| Ω (om, deg) | 74.914412 |
| ω (w, deg) | 352.020837 |
| M (ma, deg) | 287.544902 |
等級
散乱 + 全体線形
$$ M_a = (11.194 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 11.194 |
| n | 2.000 |
| gf | 1.000 |
| gb | -0.507 |
| 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 | -6.442 |
| 2025-08-01 | 2025-12-19 | +3.7586 | -1.829 |
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) |
|---|---|---|---|---|
| 2026-03-26 00:00 | 04:51:03.63 | +32:38:00.0 | HIP 22559 | 15.66 |
| 2026-03-26 12:00 | 04:52:02.41 | +32:41:37.6 | HIP 22559 | 15.20 |
| 2026-03-27 00:00 | 04:53:01.37 | +32:45:13.2 | HIP 22559 | 23.45 |
| 2026-03-27 12:00 | 04:54:00.50 | +32:48:46.9 | HIP 22898 | 18.98 |
| 2026-03-28 00:00 | 04:54:59.82 | +32:52:18.7 | HIP 22898 | 8.32 |
| 2026-03-28 12:00 | 04:55:59.31 | +32:55:48.6 | HIP 22898 | 10.66 |
| 2026-03-29 00:00 | 04:56:58.98 | +32:59:16.5 | HIP 23015 | 10.69 |
| 2026-03-29 12:00 | 04:57:58.82 | +33:02:42.5 | HIP 23015 | 14.37 |
| 2026-03-30 00:00 | 04:58:58.84 | +33:06:06.5 | HIP 23015 | 25.26 |
| 2026-03-30 12:00 | 04:59:59.02 | +33:09:28.6 | HIP 23378 | 25.08 |
| 2026-03-31 00:00 | 05:00:59.37 | +33:12:48.8 | HIP 23378 | 19.84 |
| 2026-03-31 12:00 | 05:01:59.88 | +33:16:06.9 | HIP 23378 | 22.36 |
| 2026-04-01 00:00 | 05:03:00.56 | +33:19:23.1 | HIP 23578 | 14.85 |
| 2026-04-01 12:00 | 05:04:01.40 | +33:22:37.4 | HIP 23578 | 7.09 |
| 2026-04-02 00:00 | 05:05:02.40 | +33:25:49.7 | HIP 23578 | 14.98 |
| 2026-04-02 12:00 | 05:06:03.56 | +33:29:00.0 | HIP 23733 | 26.14 |
| 2026-04-03 00:00 | 05:07:04.88 | +33:32:08.3 | HIP 23733 | 25.82 |
| 2026-04-03 12:00 | 05:08:06.35 | +33:35:14.6 | HIP 23971 | 23.96 |
| 2026-04-04 00:00 | 05:09:07.97 | +33:38:18.9 | HIP 23971 | 23.21 |
| 2026-04-04 12:00 | 05:10:09.75 | +33:41:21.3 | HIP 24226 | 28.91 |
| 2026-04-05 00:00 | 05:11:11.68 | +33:44:21.6 | HIP 24226 | 17.30 |
| 2026-04-05 12:00 | 05:12:13.76 | +33:47:20.0 | HIP 24226 | 10.63 |
| 2026-04-06 00:00 | 05:13:15.98 | +33:50:16.3 | HIP 24287 | 16.46 |
| 2026-04-06 12:00 | 05:14:18.35 | +33:53:10.7 | HIP 24287 | 22.99 |
| 2026-04-07 00:00 | 05:15:20.87 | +33:56:03.0 | HIP 24575 | 25.59 |
| 2026-04-07 12:00 | 05:16:23.53 | +33:58:53.3 | HIP 24575 | 19.88 |
| 2026-04-08 00:00 | 05:17:26.33 | +34:01:41.6 | HIP 24740 | 19.07 |
| 2026-04-08 12:00 | 05:18:29.27 | +34:04:27.9 | HIP 24832 | 12.48 |
| 2026-04-09 00:00 | 05:19:32.35 | +34:07:12.2 | HIP 24832 | 8.27 |
| 2026-04-09 12:00 | 05:20:35.56 | +34:09:54.4 | HIP 24962 | 6.82 |
| 2026-04-10 00:00 | 05:21:38.91 | +34:12:34.6 | HIP 24962 | 10.70 |
| 2026-04-10 12:00 | 05:22:42.40 | +34:15:12.8 | HIP 24962 | 23.25 |
| 2026-04-11 00:00 | 05:23:46.01 | +34:17:49.0 | HIP 25357 | 21.14 |
| 2026-04-11 12:00 | 05:24:49.76 | +34:20:23.1 | HIP 25357 | 11.95 |
| 2026-04-12 00:00 | 05:25:53.63 | +34:22:55.2 | HIP 25471 | 11.40 |
| 2026-04-12 12:00 | 05:26:57.64 | +34:25:25.2 | HIP 25471 | 2.64 |
| 2026-04-13 00:00 | 05:28:01.77 | +34:27:53.2 | HIP 25541 | 4.76 |
| 2026-04-13 12:00 | 05:29:06.02 | +34:30:19.1 | HIP 25624 | 14.12 |
| 2026-04-14 00:00 | 05:30:10.39 | +34:32:43.0 | HIP 25787 | 20.85 |
| 2026-04-14 12:00 | 05:31:14.89 | +34:35:04.9 | HIP 25906 | 18.91 |
| 2026-04-15 00:00 | 05:32:19.51 | +34:37:24.7 | HIP 25906 | 17.00 |
| 2026-04-15 12:00 | 05:33:24.24 | +34:39:42.4 | HIP 26071 | 4.79 |
| 2026-04-16 00:00 | 05:34:29.09 | +34:41:58.1 | HIP 26118 | 5.21 |