C/2025 Q3 (ATLAS)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/2025 Q3 (ATLAS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2026-02-25T15:17:11.676480Z |
| Orbit solution date (soln_date, UTC) | 2026-07-28T14:12:17Z |
| Obs used | 1443 |
| NEO | - |
| M1 | 8.100 |
| K1 | 19.750 |
| 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) | 2025-11-20.0000000 |
| e | 0.99731001 |
| q (au) | 2.112542 |
| a (au) | 785.333373 |
| i (deg) | 90.186983 |
| Ω (om, deg) | 233.144049 |
| ω (w, deg) | 218.453616 |
| M (ma, deg) | 359.995627 |
等級
散乱 + 全体線形
$$ M_a = (8.972 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 8.972 |
| n | 6.000 |
| gf | 0.998 |
| gb | -0.939 |
| 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 | 2025-10-05 | -5.9389 | +3.051 |
| 2025-10-05 | 2025-11-24 | +8.2138 | -3.009 |
| 2025-11-24 | 2026-02-25 | +10.0171 | -3.487 |
| 2026-02-25 | 2026-07-25 | +9.6902 | -4.264 |
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 | 10:50:42.60 | -61:09:43.8 | HIP 53007 | 6.45 |
| 2026-09-20 12:00 | 10:52:26.35 | -61:12:42.6 | HIP 53007 | 13.25 |
| 2026-09-21 00:00 | 10:54:09.88 | -61:15:39.5 | HIP 53121 | 18.31 |
| 2026-09-21 12:00 | 10:55:53.19 | -61:18:34.3 | HIP 53397 | 22.56 |
| 2026-09-22 00:00 | 10:57:36.27 | -61:21:27.2 | HIP 53701 | 11.93 |
| 2026-09-22 12:00 | 10:59:19.14 | -61:24:18.1 | HIP 53701 | 5.09 |
| 2026-09-23 00:00 | 11:01:01.77 | -61:27:07.1 | HIP 53880 | 4.80 |
| 2026-09-23 12:00 | 11:02:44.18 | -61:29:54.1 | HIP 53880 | 11.63 |
| 2026-09-24 00:00 | 11:04:26.35 | -61:32:39.3 | HIP 54348 | 19.39 |
| 2026-09-24 12:00 | 11:06:08.29 | -61:35:22.6 | HIP 54348 | 7.02 |
| 2026-09-25 00:00 | 11:07:50.00 | -61:38:04.1 | HIP 54348 | 5.61 |
| 2026-09-25 12:00 | 11:09:31.47 | -61:40:43.7 | HIP 54524 | 11.06 |
| 2026-09-26 00:00 | 11:11:12.69 | -61:43:21.6 | HIP 54715 | 7.07 |
| 2026-09-26 12:00 | 11:12:53.68 | -61:45:57.7 | HIP 54780 | 0.56 |
| 2026-09-27 00:00 | 11:14:34.42 | -61:48:32.0 | HIP 54780 | 12.15 |
| 2026-09-27 12:00 | 11:16:14.91 | -61:51:04.6 | HIP 55078 | 16.01 |
| 2026-09-28 00:00 | 11:17:55.16 | -61:53:35.6 | HIP 55163 | 15.62 |
| 2026-09-28 12:00 | 11:19:35.16 | -61:56:04.8 | HIP 55163 | 22.76 |
| 2026-09-29 00:00 | 11:21:14.91 | -61:58:32.4 | HIP 55557 | 12.48 |
| 2026-09-29 12:00 | 11:22:54.40 | -62:00:58.4 | HIP 55557 | 3.82 |
| 2026-09-30 00:00 | 11:24:33.65 | -62:03:22.8 | HIP 55557 | 12.51 |
| 2026-09-30 12:00 | 11:26:12.63 | -62:05:45.6 | HIP 55978 | 14.80 |
| 2026-10-01 00:00 | 11:27:51.36 | -62:08:06.9 | HIP 55978 | 5.32 |
| 2026-10-01 12:00 | 11:29:29.83 | -62:10:26.6 | HIP 55978 | 10.72 |
| 2026-10-02 00:00 | 11:31:08.04 | -62:12:44.9 | HIP 56335 | 18.62 |
| 2026-10-02 12:00 | 11:32:45.99 | -62:15:01.6 | HIP 56335 | 11.61 |
| 2026-10-03 00:00 | 11:34:23.68 | -62:17:17.0 | HIP 56335 | 13.84 |
| 2026-10-03 12:00 | 11:36:01.10 | -62:19:30.9 | HIP 56660 | 12.06 |
| 2026-10-04 00:00 | 11:37:38.25 | -62:21:43.4 | HIP 56723 | 6.49 |
| 2026-10-04 12:00 | 11:39:15.14 | -62:23:54.5 | HIP 56929 | 7.35 |
| 2026-10-05 00:00 | 11:40:51.76 | -62:26:04.3 | HIP 56929 | 4.12 |
| 2026-10-05 12:00 | 11:42:28.11 | -62:28:12.8 | HIP 57106 | 0.52 |
| 2026-10-06 00:00 | 11:44:04.18 | -62:30:20.0 | HIP 57175 | 3.93 |
| 2026-10-06 12:00 | 11:45:39.98 | -62:32:25.9 | HIP 57511 | 12.95 |
| 2026-10-07 00:00 | 11:47:15.51 | -62:34:30.5 | HIP 57511 | 8.34 |
| 2026-10-07 12:00 | 11:48:50.76 | -62:36:33.9 | HIP 57741 | 11.35 |
| 2026-10-08 00:00 | 11:50:25.73 | -62:38:36.1 | HIP 57741 | 0.40 |
| 2026-10-08 12:00 | 11:52:00.43 | -62:40:37.1 | HIP 57741 | 10.82 |
| 2026-10-09 00:00 | 11:53:34.84 | -62:42:36.9 | HIP 57978 | 8.52 |
| 2026-10-09 12:00 | 11:55:08.97 | -62:44:35.5 | HIP 57978 | 12.72 |
| 2026-10-10 00:00 | 11:56:42.82 | -62:46:33.1 | HIP 58456 | 17.32 |
| 2026-10-10 12:00 | 11:58:16.39 | -62:48:29.5 | HIP 58456 | 6.88 |
| 2026-10-11 00:00 | 11:59:49.67 | -62:50:24.8 | HIP 58498 | 0.52 |