240P/NEAT
メタデータ
| 項目 | 値 |
|---|---|
| Designation | 240P/NEAT |
| Type | P |
| Perihelion (tp_cal, UTC) | 2025-12-19T20:50:58.237440Z |
| Orbit solution date (soln_date, UTC) | 2026-06-09T12:45:02Z |
| Obs used | 4121 |
| 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) | 2024-07-16.0000000 |
| e | 0.45033420 |
| q (au) | 2.122510 |
| a (au) | 3.861455 |
| i (deg) | 23.536972 |
| Ω (om, deg) | 74.914405 |
| ω (w, deg) | 352.027190 |
| M (ma, deg) | 292.214187 |
等級
散乱 + 全体線形
$$ M_a = (13.123 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 13.123 |
| n | 2.000 |
| gf | 1.000 |
| gb | -0.500 |
| k | 0.800 |
| δ90 | 2.964 |
| 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 | 2025-07-02 | +17.2730 | -7.993 |
| 2025-07-02 | 2025-12-19 | -7.8090 | +1.764 |
| 2025-12-19 | 2026-05-26 | +15.3323 | -5.270 |
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) |
|---|---|---|---|---|
| 2026-09-20 00:00 | 11:00:26.72 | +25:11:20.9 | HIP 53861 | 9.49 |
| 2026-09-20 12:00 | 11:01:16.23 | +25:07:54.6 | HIP 53861 | 5.74 |
| 2026-09-21 00:00 | 11:02:05.64 | +25:04:28.7 | HIP 53861 | 15.81 |
| 2026-09-21 12:00 | 11:02:54.96 | +25:01:03.3 | HIP 53861 | 27.19 |
| 2026-09-22 00:00 | 11:03:44.16 | +24:57:38.4 | HIP 54196 | 25.29 |
| 2026-09-22 12:00 | 11:04:33.27 | +24:54:14.0 | HIP 54196 | 20.31 |
| 2026-09-23 00:00 | 11:05:22.28 | +24:50:50.1 | HIP 54196 | 21.34 |
| 2026-09-23 12:00 | 11:06:11.19 | +24:47:26.8 | HIP 54196 | 27.69 |
| 2026-09-24 00:00 | 11:07:00.00 | +24:44:03.9 | HIP 54487 | 25.19 |
| 2026-09-24 12:00 | 11:07:48.71 | +24:40:41.6 | HIP 54487 | 13.77 |
| 2026-09-25 00:00 | 11:08:37.32 | +24:37:19.9 | HIP 54487 | 3.45 |
| 2026-09-25 12:00 | 11:09:25.82 | +24:33:58.7 | HIP 54487 | 10.01 |
| 2026-09-26 00:00 | 11:10:14.23 | +24:30:38.1 | HIP 54487 | 21.29 |
| 2026-09-26 12:00 | 11:11:02.54 | +24:27:18.0 | HIP 54741 | 23.18 |
| 2026-09-27 00:00 | 11:11:50.74 | +24:23:58.6 | HIP 54741 | 17.60 |
| 2026-09-27 12:00 | 11:12:38.85 | +24:20:39.7 | HIP 54741 | 18.55 |
| 2026-09-28 00:00 | 11:13:26.86 | +24:17:21.4 | HIP 54741 | 25.28 |
| 2026-09-28 12:00 | 11:14:14.76 | +24:14:03.8 | HIP 54871 | 23.57 |
| 2026-09-29 00:00 | 11:15:02.57 | +24:10:46.8 | HIP 55061 | 17.72 |
| 2026-09-29 12:00 | 11:15:50.28 | +24:07:30.4 | HIP 55061 | 9.01 |
| 2026-09-30 00:00 | 11:16:37.88 | +24:04:14.6 | HIP 55061 | 10.30 |
| 2026-09-30 12:00 | 11:17:25.39 | +24:00:59.5 | HIP 55061 | 19.67 |
| 2026-10-01 00:00 | 11:18:12.79 | +23:57:45.1 | HIP 55061 | 30.38 |
| 2026-10-01 12:00 | 11:19:00.10 | +23:54:31.3 | HIP 55398 | 28.26 |
| 2026-10-02 00:00 | 11:19:47.31 | +23:51:18.2 | HIP 55398 | 18.31 |
| 2026-10-02 12:00 | 11:20:34.41 | +23:48:05.9 | HIP 55398 | 11.23 |
| 2026-10-03 00:00 | 11:21:21.41 | +23:44:54.2 | HIP 55398 | 13.03 |
| 2026-10-03 12:00 | 11:22:08.32 | +23:41:43.2 | HIP 55398 | 21.56 |
| 2026-10-04 00:00 | 11:22:55.12 | +23:38:33.0 | HIP 55660 | 18.46 |
| 2026-10-04 12:00 | 11:23:41.82 | +23:35:23.5 | HIP 55660 | 7.60 |
| 2026-10-05 00:00 | 11:24:28.42 | +23:32:14.8 | HIP 55660 | 4.80 |
| 2026-10-05 12:00 | 11:25:14.91 | +23:29:06.8 | HIP 55660 | 15.34 |
| 2026-10-06 00:00 | 11:26:01.31 | +23:25:59.7 | HIP 55895 | 20.53 |
| 2026-10-06 12:00 | 11:26:47.60 | +23:22:53.3 | HIP 55895 | 9.49 |
| 2026-10-07 00:00 | 11:27:33.79 | +23:19:47.7 | HIP 55895 | 1.89 |
| 2026-10-07 12:00 | 11:28:19.87 | +23:16:42.9 | HIP 55966 | 5.96 |
| 2026-10-08 00:00 | 11:29:05.86 | +23:13:38.9 | HIP 55966 | 13.64 |
| 2026-10-08 12:00 | 11:29:51.73 | +23:10:35.8 | HIP 55966 | 24.03 |
| 2026-10-09 00:00 | 11:30:37.51 | +23:07:33.5 | HIP 56207 | 21.06 |
| 2026-10-09 12:00 | 11:31:23.17 | +23:04:32.1 | HIP 56207 | 15.47 |
| 2026-10-10 00:00 | 11:32:08.74 | +23:01:31.5 | HIP 56207 | 16.57 |
| 2026-10-10 12:00 | 11:32:54.19 | +22:58:31.9 | HIP 56446 | 21.02 |
| 2026-10-11 00:00 | 11:33:39.54 | +22:55:33.1 | HIP 56446 | 10.17 |