C/2025 Q3 (ATLAS)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/2025 Q3 (ATLAS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2026-02-25T15:16:12.112320Z |
| Orbit solution date (soln_date, UTC) | 2026-03-31T09:42:19Z |
| Obs used | 1389 |
| NEO | - |
| M1 | 8.000 |
| K1 | 20.000 |
| PC | 0.030 |
| Discovery observation (MPC, UTC) | 2025-08-20T13:35:03.868800Z |
| Discovery magnitude (MPC) | 19.53 o |
| Discovery observatory (MPC) | T05 · ATLAS-HKO, Haleakala |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2025-11-16.0000000 |
| e | 0.99732111 |
| q (au) | 2.112549 |
| a (au) | 788.590829 |
| i (deg) | 90.187246 |
| Ω (om, deg) | 233.144034 |
| ω (w, deg) | 218.453281 |
| M (ma, deg) | 359.995476 |
等級
散乱 + 全体線形
$$ M_a = (9.042 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 9.042 |
| n | 6.000 |
| gf | 1.000 |
| gb | -0.923 |
| 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 |
|---|---|---|---|
| 2025-08-20 | 2026-02-25 | +3.3989 | -1.209 |
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 | 02:54:54.32 | -23:13:30.3 | HIP 13663 | 14.06 |
| 2026-03-26 12:00 | 02:55:33.70 | -23:17:26.3 | HIP 13663 | 6.54 |
| 2026-03-27 00:00 | 02:56:13.27 | -23:21:23.1 | HIP 13663 | 9.12 |
| 2026-03-27 12:00 | 02:56:53.04 | -23:25:20.6 | HIP 13663 | 17.92 |
| 2026-03-28 00:00 | 02:57:33.00 | -23:29:18.8 | HIP 13835 | 10.29 |
| 2026-03-28 12:00 | 02:58:13.15 | -23:33:17.8 | HIP 13835 | 3.52 |
| 2026-03-29 00:00 | 02:58:53.50 | -23:37:17.5 | HIP 13920 | 7.13 |
| 2026-03-29 12:00 | 02:59:34.05 | -23:41:18.1 | HIP 13920 | 3.44 |
| 2026-03-30 00:00 | 03:00:14.79 | -23:45:19.5 | HIP 13920 | 13.36 |
| 2026-03-30 12:00 | 03:00:55.72 | -23:49:21.8 | HIP 14072 | 12.69 |
| 2026-03-31 00:00 | 03:01:36.85 | -23:53:24.9 | HIP 14072 | 8.31 |
| 2026-03-31 12:00 | 03:02:18.17 | -23:57:28.9 | HIP 14130 | 8.92 |
| 2026-04-01 00:00 | 03:02:59.68 | -24:01:33.9 | HIP 14130 | 16.68 |
| 2026-04-01 12:00 | 03:03:41.39 | -24:05:39.7 | HIP 14130 | 26.31 |
| 2026-04-02 00:00 | 03:04:23.29 | -24:09:46.5 | HIP 14396 | 18.17 |
| 2026-04-02 12:00 | 03:05:05.39 | -24:13:54.3 | HIP 14396 | 8.52 |
| 2026-04-03 00:00 | 03:05:47.68 | -24:18:03.0 | HIP 14396 | 5.82 |
| 2026-04-03 12:00 | 03:06:30.17 | -24:22:12.7 | HIP 14396 | 14.72 |
| 2026-04-04 00:00 | 03:07:12.85 | -24:26:23.5 | HIP 14568 | 22.75 |
| 2026-04-04 12:00 | 03:07:55.73 | -24:30:35.3 | HIP 14568 | 15.21 |
| 2026-04-05 00:00 | 03:08:38.80 | -24:34:48.2 | HIP 14568 | 13.06 |
| 2026-04-05 12:00 | 03:09:22.07 | -24:39:02.2 | HIP 14623 | 15.77 |
| 2026-04-06 00:00 | 03:10:05.54 | -24:43:17.2 | HIP 14798 | 15.64 |
| 2026-04-06 12:00 | 03:10:49.20 | -24:47:33.4 | HIP 14798 | 4.92 |
| 2026-04-07 00:00 | 03:11:33.06 | -24:51:50.7 | HIP 14798 | 6.10 |
| 2026-04-07 12:00 | 03:12:17.12 | -24:56:09.2 | HIP 14798 | 16.93 |
| 2026-04-08 00:00 | 03:13:01.37 | -25:00:28.9 | HIP 15016 | 10.80 |
| 2026-04-08 12:00 | 03:13:45.82 | -25:04:49.7 | HIP 15016 | 12.57 |
| 2026-04-09 00:00 | 03:14:30.47 | -25:09:11.8 | HIP 15190 | 17.25 |
| 2026-04-09 12:00 | 03:15:15.32 | -25:13:35.1 | HIP 15190 | 8.10 |
| 2026-04-10 00:00 | 03:16:00.37 | -25:17:59.7 | HIP 15190 | 8.88 |
| 2026-04-10 12:00 | 03:16:45.61 | -25:22:25.6 | HIP 15190 | 18.44 |
| 2026-04-11 00:00 | 03:17:31.06 | -25:26:52.8 | HIP 15418 | 16.50 |
| 2026-04-11 12:00 | 03:18:16.70 | -25:31:21.3 | HIP 15418 | 8.33 |
| 2026-04-12 00:00 | 03:19:02.55 | -25:35:51.1 | HIP 15486 | 7.94 |
| 2026-04-12 12:00 | 03:19:48.60 | -25:40:22.3 | HIP 15486 | 6.18 |
| 2026-04-13 00:00 | 03:20:34.84 | -25:44:54.9 | HIP 15486 | 16.47 |
| 2026-04-13 12:00 | 03:21:21.29 | -25:49:28.8 | HIP 15700 | 18.85 |
| 2026-04-14 00:00 | 03:22:07.94 | -25:54:04.2 | HIP 15700 | 18.90 |
| 2026-04-14 12:00 | 03:22:54.80 | -25:58:41.1 | HIP 15769 | 9.19 |
| 2026-04-15 00:00 | 03:23:41.85 | -26:03:19.4 | HIP 15842 | 5.07 |
| 2026-04-15 12:00 | 03:24:29.11 | -26:07:59.1 | HIP 15842 | 8.11 |
| 2026-04-16 00:00 | 03:25:16.57 | -26:12:40.4 | HIP 15834 | 17.43 |