C/2025 T1 (ATLAS)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/2025 T1 (ATLAS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2025-12-02T08:58:56.936640Z |
| Orbit solution date (soln_date, UTC) | 2026-01-07T15:42:50Z |
| Obs used | 723 |
| NEO | - |
| M1 | 10.800 |
| K1 | 37.750 |
| 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) | 2025-11-20.0000000 |
| e | 0.99987577 |
| q (au) | 1.108827 |
| a (au) | 8925.855545 |
| i (deg) | 123.432522 |
| Ω (om, deg) | 140.494716 |
| ω (w, deg) | 114.139793 |
| M (ma, deg) | 359.999986 |
等級
散乱 + 全体線形
$$ M_a = (11.535 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 11.535 |
| n | 6.000 |
| gf | 1.000 |
| gb | -1.000 |
| 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 | +39.5714 | -3.296 |
| 2025-12-02 | 2026-01-20 | +13.6912 | -2.032 |
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) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 21:24:28.71 | -12:29:01.7 | HIP 105668 | 24.03 |
| 2026-02-03 12:00 | 21:25:04.53 | -12:36:31.7 | HIP 105668 | 20.71 |
| 2026-02-04 00:00 | 21:25:40.22 | -12:43:58.7 | HIP 105668 | 23.33 |
| 2026-02-04 12:00 | 21:26:15.79 | -12:51:22.8 | HIP 105668 | 30.33 |
| 2026-02-05 00:00 | 21:26:51.23 | -12:58:44.2 | HIP 105946 | 37.34 |
| 2026-02-05 12:00 | 21:27:26.55 | -13:06:02.8 | HIP 105946 | 29.22 |
| 2026-02-06 00:00 | 21:28:01.75 | -13:13:18.7 | HIP 105946 | 23.86 |
| 2026-02-06 12:00 | 21:28:36.84 | -13:20:32.1 | HIP 105946 | 23.17 |
| 2026-02-07 00:00 | 21:29:11.80 | -13:27:42.9 | HIP 106068 | 20.24 |
| 2026-02-07 12:00 | 21:29:46.65 | -13:34:51.2 | HIP 106068 | 16.61 |
| 2026-02-08 00:00 | 21:30:21.39 | -13:41:57.1 | HIP 106068 | 19.67 |
| 2026-02-08 12:00 | 21:30:56.02 | -13:49:00.7 | HIP 106115 | 22.31 |
| 2026-02-09 00:00 | 21:31:30.53 | -13:56:02.0 | HIP 106199 | 24.64 |
| 2026-02-09 12:00 | 21:32:04.93 | -14:03:01.1 | HIP 106199 | 25.08 |
| 2026-02-10 00:00 | 21:32:39.23 | -14:09:58.0 | HIP 106374 | 18.10 |
| 2026-02-10 12:00 | 21:33:13.41 | -14:16:52.8 | HIP 106374 | 13.76 |
| 2026-02-11 00:00 | 21:33:47.49 | -14:23:45.6 | HIP 106374 | 16.83 |
| 2026-02-11 12:00 | 21:34:21.47 | -14:30:36.4 | HIP 106525 | 7.68 |
| 2026-02-12 00:00 | 21:34:55.33 | -14:37:25.3 | HIP 106584 | 4.57 |
| 2026-02-12 12:00 | 21:35:29.10 | -14:44:12.4 | HIP 106584 | 9.14 |
| 2026-02-13 00:00 | 21:36:02.76 | -14:50:57.6 | HIP 106584 | 19.23 |
| 2026-02-13 12:00 | 21:36:36.31 | -14:57:41.2 | HIP 106829 | 23.78 |
| 2026-02-14 00:00 | 21:37:09.77 | -15:04:23.0 | HIP 106829 | 18.32 |
| 2026-02-14 12:00 | 21:37:43.12 | -15:11:03.2 | HIP 106710 | 17.03 |
| 2026-02-15 00:00 | 21:38:16.38 | -15:17:41.8 | HIP 106710 | 20.22 |
| 2026-02-15 12:00 | 21:38:49.53 | -15:24:19.0 | HIP 106710 | 27.25 |
| 2026-02-16 00:00 | 21:39:22.58 | -15:30:54.6 | HIP 106961 | 30.11 |
| 2026-02-16 12:00 | 21:39:55.54 | -15:37:28.9 | HIP 106961 | 22.92 |
| 2026-02-17 00:00 | 21:40:28.39 | -15:44:01.8 | HIP 106961 | 18.88 |
| 2026-02-17 12:00 | 21:41:01.15 | -15:50:33.5 | HIP 107108 | 17.02 |
| 2026-02-18 00:00 | 21:41:33.80 | -15:57:03.9 | HIP 107176 | 18.27 |
| 2026-02-18 12:00 | 21:42:06.36 | -16:03:33.1 | HIP 107176 | 18.99 |
| 2026-02-19 00:00 | 21:42:38.83 | -16:10:01.2 | HIP 107176 | 24.36 |
| 2026-02-19 12:00 | 21:43:11.19 | -16:16:28.2 | HIP 107324 | 24.39 |
| 2026-02-20 00:00 | 21:43:43.46 | -16:22:54.2 | HIP 107359 | 16.52 |
| 2026-02-20 12:00 | 21:44:15.63 | -16:29:19.2 | HIP 107359 | 6.72 |
| 2026-02-21 00:00 | 21:44:47.70 | -16:35:43.3 | HIP 107359 | 4.33 |
| 2026-02-21 12:00 | 21:45:19.68 | -16:42:06.5 | HIP 107359 | 13.84 |
| 2026-02-22 00:00 | 21:45:51.56 | -16:48:28.9 | HIP 107524 | 21.84 |
| 2026-02-22 12:00 | 21:46:23.34 | -16:54:50.5 | HIP 107524 | 12.97 |
| 2026-02-23 00:00 | 21:46:55.03 | -17:01:11.4 | HIP 107524 | 7.46 |
| 2026-02-23 12:00 | 21:47:26.62 | -17:07:31.6 | HIP 107594 | 10.42 |
| 2026-02-24 00:00 | 21:47:58.12 | -17:13:51.2 | HIP 107594 | 6.44 |