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) |
|---|---|---|---|---|
| 2026-07-29 00:00 | 09:23:39.58 | +31:25:06.1 | HIP 46302 | 39.81 |
| 2026-07-29 12:00 | 09:24:39.49 | +31:21:49.3 | HIP 46302 | 26.72 |
| 2026-07-30 00:00 | 09:25:39.31 | +31:18:31.9 | HIP 46302 | 13.88 |
| 2026-07-30 12:00 | 09:26:39.04 | +31:15:13.8 | HIP 46302 | 4.40 |
| 2026-07-31 00:00 | 09:27:38.66 | +31:11:55.0 | HIP 46302 | 13.90 |
| 2026-07-31 12:00 | 09:28:38.20 | +31:08:35.7 | HIP 46446 | 15.06 |
| 2026-08-01 00:00 | 09:29:37.63 | +31:05:15.7 | HIP 46604 | 16.12 |
| 2026-08-01 12:00 | 09:30:36.97 | +31:01:55.1 | HIP 46604 | 18.51 |
| 2026-08-02 00:00 | 09:31:36.21 | +30:58:33.9 | HIP 46604 | 27.75 |
| 2026-08-02 12:00 | 09:32:35.35 | +30:55:12.2 | HIP 46868 | 21.80 |
| 2026-08-03 00:00 | 09:33:34.40 | +30:51:49.8 | HIP 46868 | 19.00 |
| 2026-08-03 12:00 | 09:34:33.35 | +30:48:26.9 | HIP 46993 | 14.88 |
| 2026-08-04 00:00 | 09:35:32.21 | +30:45:03.5 | HIP 46993 | 15.80 |
| 2026-08-04 12:00 | 09:36:30.96 | +30:41:39.5 | HIP 47222 | 19.81 |
| 2026-08-05 00:00 | 09:37:29.63 | +30:38:14.9 | HIP 47324 | 16.04 |
| 2026-08-05 12:00 | 09:38:28.19 | +30:34:49.9 | HIP 47324 | 10.98 |
| 2026-08-06 00:00 | 09:39:26.66 | +30:31:24.3 | HIP 47361 | 16.00 |
| 2026-08-06 12:00 | 09:40:25.04 | +30:27:58.2 | HIP 47361 | 21.74 |
| 2026-08-07 00:00 | 09:41:23.31 | +30:24:31.6 | HIP 47636 | 25.03 |
| 2026-08-07 12:00 | 09:42:21.49 | +30:21:04.6 | HIP 47636 | 15.23 |
| 2026-08-08 00:00 | 09:43:19.58 | +30:17:37.1 | HIP 47636 | 13.29 |
| 2026-08-08 12:00 | 09:44:17.57 | +30:14:09.1 | HIP 47701 | 18.37 |
| 2026-08-09 00:00 | 09:45:15.46 | +30:10:40.7 | HIP 47939 | 21.53 |
| 2026-08-09 12:00 | 09:46:13.25 | +30:07:11.9 | HIP 47939 | 21.67 |
| 2026-08-10 00:00 | 09:47:10.95 | +30:03:42.7 | HIP 47939 | 28.48 |
| 2026-08-10 12:00 | 09:48:08.55 | +30:00:13.0 | HIP 48158 | 25.07 |
| 2026-08-11 00:00 | 09:49:06.05 | +29:56:43.0 | HIP 48158 | 26.17 |
| 2026-08-11 12:00 | 09:50:03.46 | +29:53:12.5 | HIP 48160 | 28.04 |
| 2026-08-12 00:00 | 09:51:00.77 | +29:49:41.7 | HIP 48387 | 31.89 |
| 2026-08-12 12:00 | 09:51:57.98 | +29:46:10.6 | HIP 48387 | 33.63 |
| 2026-08-13 00:00 | 09:52:55.09 | +29:42:39.1 | HIP 48544 | 33.29 |
| 2026-08-13 12:00 | 09:53:52.11 | +29:39:07.3 | HIP 48544 | 26.45 |
| 2026-08-14 00:00 | 09:54:49.02 | +29:35:35.1 | HIP 48713 | 20.89 |
| 2026-08-14 12:00 | 09:55:45.84 | +29:32:02.7 | HIP 48713 | 16.05 |
| 2026-08-15 00:00 | 09:56:42.55 | +29:28:29.9 | HIP 48713 | 20.21 |
| 2026-08-15 12:00 | 09:57:39.17 | +29:24:56.9 | HIP 48898 | 13.12 |
| 2026-08-16 00:00 | 09:58:35.69 | +29:21:23.5 | HIP 48898 | 10.75 |
| 2026-08-16 12:00 | 09:59:32.11 | +29:17:50.0 | HIP 48898 | 19.67 |
| 2026-08-17 00:00 | 10:00:28.43 | +29:14:16.1 | HIP 49109 | 23.87 |
| 2026-08-17 12:00 | 10:01:24.65 | +29:10:42.1 | HIP 49103 | 23.68 |
| 2026-08-18 00:00 | 10:02:20.77 | +29:07:07.7 | HIP 49103 | 24.27 |
| 2026-08-18 12:00 | 10:03:16.79 | +29:03:33.2 | HIP 49103 | 30.72 |
| 2026-08-19 00:00 | 10:04:12.71 | +28:59:58.5 | HIP 49443 | 25.18 |