C/2025 L1 (ATLAS)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/2025 L1 (ATLAS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2026-01-12T17:37:29.809920Z |
| Orbit solution date (soln_date, UTC) | 2026-09-08T09:12:18Z |
| Obs used | 137 |
| NEO | - |
| M1 | 14.300 |
| K1 | 4.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2025-06-06T09:16:16.579200Z |
| Discovery magnitude (MPC) | 18.22 c |
| 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) | 2025-10-25.0000000 |
| e | 1.00148051 |
| q (au) | 1.679668 |
| a (au) | -1134.522447 |
| i (deg) | 114.136816 |
| Ω (om, deg) | 208.109361 |
| ω (w, deg) | 341.249899 |
| M (ma, deg) | -0.002057 |
等級
散乱 + 全体線形
$$ M_a = (16.173 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 16.173 |
| n | 2.000 |
| gf | 1.000 |
| gb | -0.844 |
| k | 0.800 |
| 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 |
|---|---|---|---|
| 2024-10-01 | 2025-07-08 | +12.4803 | -6.404 |
| 2025-07-08 | 2026-01-05 | -1.2310 | -0.189 |
| 2026-01-13 | 2026-05-21 | +25.2081 | -6.256 |
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 | 12:43:50.69 | +50:06:12.3 | HIP 61918 | 24.80 |
| 2026-09-20 12:00 | 12:44:27.18 | +50:07:41.1 | HIP 62303 | 23.70 |
| 2026-09-21 00:00 | 12:45:03.76 | +50:09:11.9 | HIP 62303 | 21.84 |
| 2026-09-21 12:00 | 12:45:40.42 | +50:10:44.6 | HIP 62437 | 20.53 |
| 2026-09-22 00:00 | 12:46:17.17 | +50:12:19.1 | HIP 62437 | 14.89 |
| 2026-09-22 12:00 | 12:46:54.00 | +50:13:55.5 | HIP 62437 | 9.80 |
| 2026-09-23 00:00 | 12:47:30.92 | +50:15:33.9 | HIP 62437 | 6.75 |
| 2026-09-23 12:00 | 12:48:07.92 | +50:17:14.1 | HIP 62437 | 8.42 |
| 2026-09-24 00:00 | 12:48:45.00 | +50:18:56.3 | HIP 62437 | 13.14 |
| 2026-09-24 12:00 | 12:49:22.17 | +50:20:40.3 | HIP 62437 | 18.75 |
| 2026-09-25 00:00 | 12:49:59.42 | +50:22:26.3 | HIP 62818 | 23.29 |
| 2026-09-25 12:00 | 12:50:36.76 | +50:24:14.3 | HIP 62818 | 18.21 |
| 2026-09-26 00:00 | 12:51:14.18 | +50:26:04.2 | HIP 62818 | 14.08 |
| 2026-09-26 12:00 | 12:51:51.68 | +50:27:56.0 | HIP 62818 | 11.99 |
| 2026-09-27 00:00 | 12:52:29.27 | +50:29:49.8 | HIP 62818 | 12.99 |
| 2026-09-27 12:00 | 12:53:06.94 | +50:31:45.5 | HIP 62818 | 16.55 |
| 2026-09-28 00:00 | 12:53:44.70 | +50:33:43.2 | HIP 62987 | 18.99 |
| 2026-09-28 12:00 | 12:54:22.54 | +50:35:42.9 | HIP 62987 | 19.92 |
| 2026-09-29 00:00 | 12:55:00.46 | +50:37:44.6 | HIP 63198 | 20.44 |
| 2026-09-29 12:00 | 12:55:38.47 | +50:39:48.3 | HIP 63198 | 14.25 |
| 2026-09-30 00:00 | 12:56:16.56 | +50:41:54.0 | HIP 63198 | 8.31 |
| 2026-09-30 12:00 | 12:56:54.73 | +50:44:01.7 | HIP 63198 | 4.04 |
| 2026-10-01 00:00 | 12:57:32.99 | +50:46:11.4 | HIP 63198 | 6.75 |
| 2026-10-01 12:00 | 12:58:11.33 | +50:48:23.1 | HIP 63198 | 12.55 |
| 2026-10-02 00:00 | 12:58:49.76 | +50:50:36.9 | HIP 63198 | 18.78 |
| 2026-10-02 12:00 | 12:59:28.26 | +50:52:52.8 | HIP 63198 | 25.15 |
| 2026-10-03 00:00 | 13:00:06.86 | +50:55:10.7 | HIP 63666 | 27.28 |
| 2026-10-03 12:00 | 13:00:45.53 | +50:57:30.6 | HIP 63666 | 20.79 |
| 2026-10-04 00:00 | 13:01:24.29 | +50:59:52.7 | HIP 63666 | 14.33 |
| 2026-10-04 12:00 | 13:02:03.14 | +51:02:16.8 | HIP 63666 | 8.00 |
| 2026-10-05 00:00 | 13:02:42.06 | +51:04:43.1 | HIP 63666 | 3.03 |
| 2026-10-05 12:00 | 13:03:21.07 | +51:07:11.4 | HIP 63666 | 6.44 |
| 2026-10-06 00:00 | 13:04:00.17 | +51:09:41.9 | HIP 63806 | 7.08 |
| 2026-10-06 12:00 | 13:04:39.34 | +51:12:14.5 | HIP 63806 | 0.50 |
| 2026-10-07 00:00 | 13:05:18.60 | +51:14:49.2 | HIP 63806 | 6.25 |
| 2026-10-07 12:00 | 13:05:57.94 | +51:17:26.1 | HIP 63806 | 12.93 |
| 2026-10-08 00:00 | 13:06:37.36 | +51:20:05.2 | HIP 63806 | 19.64 |
| 2026-10-08 12:00 | 13:07:16.87 | +51:22:46.4 | HIP 64132 | 22.75 |
| 2026-10-09 00:00 | 13:07:56.45 | +51:25:29.9 | HIP 64194 | 21.08 |
| 2026-10-09 12:00 | 13:08:36.12 | +51:28:15.5 | HIP 64194 | 20.31 |
| 2026-10-10 00:00 | 13:09:15.87 | +51:31:03.3 | HIP 64065 | 21.42 |
| 2026-10-10 12:00 | 13:09:55.69 | +51:33:53.3 | HIP 64065 | 24.13 |
| 2026-10-11 00:00 | 13:10:35.60 | +51:36:45.5 | HIP 64468 | 26.87 |