C/2025 T1 (ATLAS)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/2025 T1 (ATLAS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2025-12-02T09:03:11.816640Z |
| Orbit solution date (soln_date, UTC) | 2026-05-05T09:12:15Z |
| Obs used | 813 |
| NEO | - |
| M1 | 11.700 |
| K1 | 24.000 |
| PC | 0.030 |
| Discovery observation (MPC, UTC) | 2025-10-11T14:54:27.014400Z |
| Discovery magnitude (MPC) | 17.50 o |
| Discovery observatory (MPC) | T08 · ATLAS-MLO, Mauna Loa |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2025-11-27.0000000 |
| e | 0.99966270 |
| q (au) | 1.108807 |
| a (au) | 3287.287384 |
| i (deg) | 123.433612 |
| Ω (om, deg) | 140.494913 |
| ω (w, deg) | 114.142671 |
| M (ma, deg) | 359.999972 |
等級
散乱 + 全体線形
$$ M_a = (11.805 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 11.805 |
| n | 6.000 |
| gf | 1.000 |
| gb | -0.923 |
| 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 |
|---|---|---|---|
| 2025-10-11 | 2025-12-02 | +40.2695 | -3.675 |
| 2025-12-02 | 2026-05-04 | +8.4663 | -2.142 |
log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)
天体暦
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 22:43:21.59 | -38:25:47.6 | HIP 112159 | 21.25 |
| 2026-05-12 12:00 | 22:43:26.40 | -38:38:21.9 | HIP 112159 | 9.72 |
| 2026-05-13 00:00 | 22:43:30.82 | -38:51:00.8 | HIP 112159 | 7.41 |
| 2026-05-13 12:00 | 22:43:34.84 | -39:03:44.2 | HIP 112090 | 15.89 |
| 2026-05-14 00:00 | 22:43:38.46 | -39:16:32.1 | HIP 112090 | 20.11 |
| 2026-05-14 12:00 | 22:43:41.68 | -39:29:24.6 | HIP 112266 | 16.74 |
| 2026-05-15 00:00 | 22:43:44.48 | -39:42:21.6 | HIP 112266 | 7.32 |
| 2026-05-15 12:00 | 22:43:46.85 | -39:55:23.1 | HIP 112185 | 7.71 |
| 2026-05-16 00:00 | 22:43:48.80 | -40:08:29.0 | HIP 112205 | 3.63 |
| 2026-05-16 12:00 | 22:43:50.31 | -40:21:39.4 | HIP 112205 | 14.45 |
| 2026-05-17 00:00 | 22:43:51.38 | -40:34:54.3 | HIP 112301 | 15.66 |
| 2026-05-17 12:00 | 22:43:52.00 | -40:48:13.6 | HIP 112301 | 11.04 |
| 2026-05-18 00:00 | 22:43:52.16 | -41:01:37.2 | HIP 112301 | 18.91 |
| 2026-05-18 12:00 | 22:43:51.86 | -41:15:05.3 | HIP 112203 | 10.59 |
| 2026-05-19 00:00 | 22:43:51.09 | -41:28:37.6 | HIP 112203 | 5.47 |
| 2026-05-19 12:00 | 22:43:49.83 | -41:42:14.3 | HIP 112186 | 11.35 |
| 2026-05-20 00:00 | 22:43:48.10 | -41:55:55.2 | HIP 112393 | 23.96 |
| 2026-05-20 12:00 | 22:43:45.86 | -42:09:40.4 | HIP 112239 | 20.18 |
| 2026-05-21 00:00 | 22:43:43.13 | -42:23:29.7 | HIP 112239 | 7.26 |
| 2026-05-21 12:00 | 22:43:39.88 | -42:37:23.2 | HIP 112239 | 9.10 |
| 2026-05-22 00:00 | 22:43:36.12 | -42:51:20.8 | HIP 112314 | 20.82 |
| 2026-05-22 12:00 | 22:43:31.83 | -43:05:22.4 | HIP 112123 | 10.71 |
| 2026-05-23 00:00 | 22:43:27.01 | -43:19:28.1 | HIP 112123 | 11.79 |
| 2026-05-23 12:00 | 22:43:21.65 | -43:33:37.7 | HIP 112123 | 23.75 |
| 2026-05-24 00:00 | 22:43:15.74 | -43:47:51.3 | HIP 112236 | 20.18 |
| 2026-05-24 12:00 | 22:43:09.27 | -44:02:08.7 | HIP 112236 | 9.91 |
| 2026-05-25 00:00 | 22:43:02.23 | -44:16:29.9 | HIP 112127 | 3.79 |
| 2026-05-25 12:00 | 22:42:54.61 | -44:30:54.9 | HIP 112207 | 7.35 |
| 2026-05-26 00:00 | 22:42:46.40 | -44:45:23.5 | HIP 112207 | 14.00 |
| 2026-05-26 12:00 | 22:42:37.61 | -44:59:55.8 | HIP 111980 | 22.41 |
| 2026-05-27 00:00 | 22:42:28.20 | -45:14:31.6 | HIP 111980 | 16.12 |
| 2026-05-27 12:00 | 22:42:18.18 | -45:29:10.9 | HIP 111975 | 15.03 |
| 2026-05-28 00:00 | 22:42:07.54 | -45:43:53.7 | HIP 111975 | 18.83 |
| 2026-05-28 12:00 | 22:41:56.26 | -45:58:39.8 | HIP 111983 | 16.76 |
| 2026-05-29 00:00 | 22:41:44.33 | -46:13:29.2 | HIP 111983 | 8.03 |
| 2026-05-29 12:00 | 22:41:31.75 | -46:28:21.9 | HIP 111901 | 15.57 |
| 2026-05-30 00:00 | 22:41:18.50 | -46:43:17.6 | HIP 111885 | 15.63 |
| 2026-05-30 12:00 | 22:41:04.58 | -46:58:16.4 | HIP 112122 | 17.09 |
| 2026-05-31 00:00 | 22:40:49.96 | -47:13:18.2 | HIP 112117 | 18.17 |
| 2026-05-31 12:00 | 22:40:34.64 | -47:28:22.8 | HIP 111994 | 9.57 |
| 2026-06-01 00:00 | 22:40:18.61 | -47:43:30.3 | HIP 111894 | 3.85 |
| 2026-06-01 12:00 | 22:40:01.85 | -47:58:40.5 | HIP 111894 | 14.04 |
| 2026-06-02 00:00 | 22:39:44.36 | -48:13:53.2 | HIP 112081 | 24.16 |