C/2024 A1 (ATLAS)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/2024 A1 (ATLAS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2025-06-13T17:27:36.414720Z |
| Orbit solution date (soln_date, UTC) | 2026-03-31T09:42:18Z |
| Obs used | 1818 |
| 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) | 2025-04-06.0000000 |
| e | 1.00196530 |
| q (au) | 3.875283 |
| a (au) | -1971.854539 |
| i (deg) | 94.453011 |
| Ω (om, deg) | 112.137940 |
| ω (w, deg) | 353.314308 |
| M (ma, deg) | -0.000774 |
等級
散乱 + 全体線形
$$ M_a = (9.333 + 2.407\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 9.333 |
| n | 2.407 |
| gf | 1.000 |
| gb | -0.500 |
| 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 | +0.7640 | -0.654 |
| 2025-09-01 | 2026-03-21 | +3.2795 | -1.777 |
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 | 06:14:10.81 | +63:43:06.9 | HIP 29548 | 19.84 |
| 2026-03-26 12:00 | 06:14:06.46 | +63:42:42.6 | HIP 29548 | 19.35 |
| 2026-03-27 00:00 | 06:14:02.64 | +63:42:18.5 | HIP 29548 | 18.88 |
| 2026-03-27 12:00 | 06:13:59.34 | +63:41:54.5 | HIP 29548 | 18.43 |
| 2026-03-28 00:00 | 06:13:56.55 | +63:41:30.7 | HIP 29548 | 17.99 |
| 2026-03-28 12:00 | 06:13:54.27 | +63:41:07.0 | HIP 29548 | 17.57 |
| 2026-03-29 00:00 | 06:13:52.50 | +63:40:43.6 | HIP 29548 | 17.16 |
| 2026-03-29 12:00 | 06:13:51.22 | +63:40:20.3 | HIP 29548 | 16.76 |
| 2026-03-30 00:00 | 06:13:50.45 | +63:39:57.4 | HIP 29548 | 16.37 |
| 2026-03-30 12:00 | 06:13:50.16 | +63:39:34.6 | HIP 29548 | 15.99 |
| 2026-03-31 00:00 | 06:13:50.37 | +63:39:12.1 | HIP 29548 | 15.62 |
| 2026-03-31 12:00 | 06:13:51.06 | +63:38:49.9 | HIP 29548 | 15.26 |
| 2026-04-01 00:00 | 06:13:52.23 | +63:38:28.0 | HIP 29548 | 14.91 |
| 2026-04-01 12:00 | 06:13:53.88 | +63:38:06.4 | HIP 29548 | 14.58 |
| 2026-04-02 00:00 | 06:13:56.01 | +63:37:45.2 | HIP 29548 | 14.27 |
| 2026-04-02 12:00 | 06:13:58.60 | +63:37:24.2 | HIP 29548 | 13.97 |
| 2026-04-03 00:00 | 06:14:01.66 | +63:37:03.6 | HIP 29548 | 13.71 |
| 2026-04-03 12:00 | 06:14:05.19 | +63:36:43.4 | HIP 29548 | 13.47 |
| 2026-04-04 00:00 | 06:14:09.17 | +63:36:23.6 | HIP 29548 | 13.27 |
| 2026-04-04 12:00 | 06:14:13.61 | +63:36:04.1 | HIP 29548 | 13.12 |
| 2026-04-05 00:00 | 06:14:18.50 | +63:35:45.1 | HIP 29548 | 13.01 |
| 2026-04-05 12:00 | 06:14:23.84 | +63:35:26.4 | HIP 29548 | 12.96 |
| 2026-04-06 00:00 | 06:14:29.63 | +63:35:08.2 | HIP 29548 | 12.98 |
| 2026-04-06 12:00 | 06:14:35.86 | +63:34:50.4 | HIP 29548 | 13.06 |
| 2026-04-07 00:00 | 06:14:42.53 | +63:34:33.0 | HIP 29548 | 13.22 |
| 2026-04-07 12:00 | 06:14:49.63 | +63:34:16.1 | HIP 29548 | 13.47 |
| 2026-04-08 00:00 | 06:14:57.17 | +63:33:59.7 | HIP 29548 | 13.80 |
| 2026-04-08 12:00 | 06:15:05.13 | +63:33:43.7 | HIP 29548 | 14.22 |
| 2026-04-09 00:00 | 06:15:13.52 | +63:33:28.2 | HIP 29548 | 14.72 |
| 2026-04-09 12:00 | 06:15:22.33 | +63:33:13.2 | HIP 29548 | 15.31 |
| 2026-04-10 00:00 | 06:15:31.57 | +63:32:58.7 | HIP 29548 | 15.99 |
| 2026-04-10 12:00 | 06:15:41.21 | +63:32:44.7 | HIP 29548 | 16.75 |
| 2026-04-11 00:00 | 06:15:51.27 | +63:32:31.2 | HIP 29548 | 17.59 |
| 2026-04-11 12:00 | 06:16:01.74 | +63:32:18.3 | HIP 29548 | 18.51 |
| 2026-04-12 00:00 | 06:16:12.62 | +63:32:05.8 | HIP 29548 | 19.51 |
| 2026-04-12 12:00 | 06:16:23.90 | +63:31:54.0 | HIP 29548 | 20.57 |
| 2026-04-13 00:00 | 06:16:35.58 | +63:31:42.6 | HIP 29548 | 21.70 |
| 2026-04-13 12:00 | 06:16:47.66 | +63:31:31.8 | HIP 29548 | 22.90 |
| 2026-04-14 00:00 | 06:17:00.13 | +63:31:21.6 | HIP 29548 | 24.16 |
| 2026-04-14 12:00 | 06:17:12.99 | +63:31:12.0 | HIP 29548 | 25.48 |
| 2026-04-15 00:00 | 06:17:26.24 | +63:31:02.9 | HIP 29548 | 26.86 |
| 2026-04-15 12:00 | 06:17:39.87 | +63:30:54.4 | HIP 29548 | 28.29 |
| 2026-04-16 00:00 | 06:17:53.89 | +63:30:46.5 | HIP 29548 | 29.78 |