C/2024 A1 (ATLAS)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/2024 A1 (ATLAS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2025-06-13T17:20:24.509760Z |
| Orbit solution date (soln_date, UTC) | 2026-05-05T09:12:14Z |
| Obs used | 1928 |
| NEO | - |
| M1 | 11.200 |
| K1 | 4.750 |
| PC | - |
| Discovery observation (MPC, UTC) | 2024-01-03T04:58:49.900800Z |
| Discovery magnitude (MPC) | 18.80 o |
| Discovery observatory (MPC) | W68 · ATLAS Chile, Rio Hurtado |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2025-04-25.0000000 |
| e | 1.00208243 |
| q (au) | 3.875284 |
| a (au) | -1860.939795 |
| i (deg) | 94.455462 |
| Ω (om, deg) | 112.137168 |
| ω (w, deg) | 353.313651 |
| M (ma, deg) | -0.000610 |
等級
散乱 + 全体線形
$$ M_a = (9.275 + 2.450\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 9.275 |
| n | 2.450 |
| gf | 0.998 |
| gb | -0.706 |
| 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 |
|---|---|---|---|
| 2024-01-03 | 2025-05-09 | +0.6562 | -0.596 |
| 2025-09-01 | 2026-05-05 | +3.3637 | -1.840 |
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 | 06:37:36.02 | +63:38:49.6 | HIP 31422 | 18.01 |
| 2026-05-12 12:00 | 06:38:06.31 | +63:39:16.5 | HIP 31422 | 21.33 |
| 2026-05-13 00:00 | 06:38:36.85 | +63:39:43.9 | HIP 31422 | 24.70 |
| 2026-05-13 12:00 | 06:39:07.64 | +63:40:12.0 | HIP 32105 | 24.78 |
| 2026-05-14 00:00 | 06:39:38.68 | +63:40:40.8 | HIP 32105 | 22.04 |
| 2026-05-14 12:00 | 06:40:09.96 | +63:41:10.2 | HIP 32105 | 19.54 |
| 2026-05-15 00:00 | 06:40:41.48 | +63:41:40.3 | HIP 32105 | 17.38 |
| 2026-05-15 12:00 | 06:41:13.25 | +63:42:11.1 | HIP 32105 | 15.72 |
| 2026-05-16 00:00 | 06:41:45.25 | +63:42:42.5 | HIP 32105 | 14.76 |
| 2026-05-16 12:00 | 06:42:17.49 | +63:43:14.5 | HIP 32105 | 14.66 |
| 2026-05-17 00:00 | 06:42:49.97 | +63:43:47.2 | HIP 32105 | 15.45 |
| 2026-05-17 12:00 | 06:43:22.69 | +63:44:20.6 | HIP 32105 | 17.02 |
| 2026-05-18 00:00 | 06:43:55.63 | +63:44:54.6 | HIP 32105 | 19.20 |
| 2026-05-18 12:00 | 06:44:28.81 | +63:45:29.3 | HIP 32105 | 21.82 |
| 2026-05-19 00:00 | 06:45:02.22 | +63:46:04.6 | HIP 32105 | 24.75 |
| 2026-05-19 12:00 | 06:45:35.85 | +63:46:40.5 | HIP 32105 | 27.90 |
| 2026-05-20 00:00 | 06:46:09.71 | +63:47:17.2 | HIP 32105 | 31.22 |
| 2026-05-20 12:00 | 06:46:43.79 | +63:47:54.4 | HIP 32105 | 34.67 |
| 2026-05-21 00:00 | 06:47:18.09 | +63:48:32.4 | HIP 32105 | 38.21 |
| 2026-05-21 12:00 | 06:47:52.62 | +63:49:10.9 | HIP 32877 | 37.57 |
| 2026-05-22 00:00 | 06:48:27.36 | +63:49:50.1 | HIP 32877 | 35.02 |
| 2026-05-22 12:00 | 06:49:02.31 | +63:50:30.0 | HIP 32877 | 32.72 |
| 2026-05-23 00:00 | 06:49:37.49 | +63:51:10.5 | HIP 33151 | 30.69 |
| 2026-05-23 12:00 | 06:50:12.87 | +63:51:51.6 | HIP 33151 | 26.75 |
| 2026-05-24 00:00 | 06:50:48.47 | +63:52:33.4 | HIP 33151 | 22.79 |
| 2026-05-24 12:00 | 06:51:24.28 | +63:53:15.7 | HIP 33151 | 18.82 |
| 2026-05-25 00:00 | 06:52:00.29 | +63:53:58.8 | HIP 33151 | 14.83 |
| 2026-05-25 12:00 | 06:52:36.52 | +63:54:42.4 | HIP 33151 | 10.85 |
| 2026-05-26 00:00 | 06:53:12.95 | +63:55:26.7 | HIP 33151 | 6.93 |
| 2026-05-26 12:00 | 06:53:49.58 | +63:56:11.6 | HIP 33151 | 3.35 |
| 2026-05-27 00:00 | 06:54:26.42 | +63:56:57.1 | HIP 33151 | 2.82 |
| 2026-05-27 12:00 | 06:55:03.46 | +63:57:43.3 | HIP 33151 | 6.23 |
| 2026-05-28 00:00 | 06:55:40.70 | +63:58:30.0 | HIP 33151 | 10.21 |
| 2026-05-28 12:00 | 06:56:18.14 | +63:59:17.4 | HIP 33151 | 14.31 |
| 2026-05-29 00:00 | 06:56:55.78 | +64:00:05.4 | HIP 33151 | 18.46 |
| 2026-05-29 12:00 | 06:57:33.62 | +64:00:54.0 | HIP 33151 | 22.66 |
| 2026-05-30 00:00 | 06:58:11.66 | +64:01:43.2 | HIP 33151 | 26.88 |
| 2026-05-30 12:00 | 06:58:49.89 | +64:02:33.0 | HIP 33956 | 26.24 |
| 2026-05-31 00:00 | 06:59:28.32 | +64:03:23.4 | HIP 33956 | 22.38 |
| 2026-05-31 12:00 | 07:00:06.94 | +64:04:14.4 | HIP 33956 | 18.70 |
| 2026-06-01 00:00 | 07:00:45.75 | +64:05:06.0 | HIP 33956 | 15.34 |
| 2026-06-01 12:00 | 07:01:24.75 | +64:05:58.2 | HIP 33956 | 12.59 |
| 2026-06-02 00:00 | 07:02:03.95 | +64:06:50.9 | HIP 33956 | 10.94 |