C/2025 A6 (Lemmon)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/2025 A6 (Lemmon) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2025-11-08T12:57:14.175360Z |
| Orbit solution date (soln_date, UTC) | 2026-05-05T09:12:15Z |
| Obs used | 1941 |
| NEO | - |
| M1 | 10.400 |
| K1 | 9.750 |
| PC | - |
| Discovery observation (MPC, UTC) | 2025-01-03T08:12:42.537600Z |
| Discovery magnitude (MPC) | 21.65 G |
| Discovery observatory (MPC) | G96 · Mt. Lemmon Survey |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2025-10-13.0000000 |
| e | 0.99556478 |
| q (au) | 0.529891 |
| a (au) | 119.473437 |
| i (deg) | 143.663669 |
| Ω (om, deg) | 108.097839 |
| ω (w, deg) | 132.971270 |
| M (ma, deg) | 359.979969 |
等級
散乱 + 全体線形
$$ M_a = (8.638 + 5.310\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 8.638 |
| n | 5.310 |
| gf | 1.000 |
| gb | -0.516 |
| k | 0.800 |
| δ90 | 9.999 |
| 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 |
|---|---|---|---|
| 2024-11-12 | 2025-09-20 | +5.6959 | -0.972 |
| 2025-09-20 | 2025-11-08 | -3.7889 | -0.101 |
| 2025-11-08 | 2026-02-06 | -6.1262 | -1.742 |
| 2026-02-06 | 2026-05-16 | +11.8996 | -6.006 |
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) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 10:55:05.41 | -46:21:45.8 | HIP 53373 | 13.42 |
| 2026-05-12 12:00 | 10:54:39.27 | -46:09:11.3 | HIP 53293 | 8.42 |
| 2026-05-13 00:00 | 10:54:14.01 | -45:56:42.3 | HIP 53293 | 8.39 |
| 2026-05-13 12:00 | 10:53:49.63 | -45:44:18.8 | HIP 53357 | 12.46 |
| 2026-05-14 00:00 | 10:53:26.10 | -45:32:00.8 | HIP 53357 | 14.19 |
| 2026-05-14 12:00 | 10:53:03.42 | -45:19:48.4 | HIP 53357 | 24.01 |
| 2026-05-15 00:00 | 10:52:41.55 | -45:07:41.7 | HIP 53199 | 29.70 |
| 2026-05-15 12:00 | 10:52:20.50 | -44:55:40.6 | HIP 53199 | 18.41 |
| 2026-05-16 00:00 | 10:52:00.23 | -44:43:45.3 | HIP 53199 | 10.56 |
| 2026-05-16 12:00 | 10:51:40.74 | -44:31:55.8 | HIP 53199 | 13.80 |
| 2026-05-17 00:00 | 10:51:22.01 | -44:20:12.0 | HIP 52927 | 20.68 |
| 2026-05-17 12:00 | 10:51:04.02 | -44:08:34.0 | HIP 52927 | 19.25 |
| 2026-05-18 00:00 | 10:50:46.76 | -43:57:01.9 | HIP 52927 | 24.57 |
| 2026-05-18 12:00 | 10:50:30.21 | -43:45:35.7 | HIP 53168 | 25.14 |
| 2026-05-19 00:00 | 10:50:14.37 | -43:34:15.3 | HIP 53168 | 25.75 |
| 2026-05-19 12:00 | 10:49:59.21 | -43:23:00.9 | HIP 52811 | 24.34 |
| 2026-05-20 00:00 | 10:49:44.72 | -43:11:52.4 | HIP 52811 | 26.68 |
| 2026-05-20 12:00 | 10:49:30.90 | -43:00:49.8 | HIP 52811 | 33.03 |
| 2026-05-21 00:00 | 10:49:17.71 | -42:49:53.1 | HIP 52924 | 27.87 |
| 2026-05-21 12:00 | 10:49:05.17 | -42:39:02.4 | HIP 52924 | 17.41 |
| 2026-05-22 00:00 | 10:48:53.24 | -42:28:17.7 | HIP 52924 | 8.66 |
| 2026-05-22 12:00 | 10:48:41.91 | -42:17:38.9 | HIP 52924 | 9.22 |
| 2026-05-23 00:00 | 10:48:31.19 | -42:07:06.1 | HIP 52848 | 10.42 |
| 2026-05-23 12:00 | 10:48:21.05 | -41:56:39.2 | HIP 52848 | 0.40 |
| 2026-05-24 00:00 | 10:48:11.47 | -41:46:18.3 | HIP 52848 | 10.70 |
| 2026-05-24 12:00 | 10:48:02.46 | -41:36:03.3 | HIP 52843 | 19.68 |
| 2026-05-25 00:00 | 10:47:54.00 | -41:25:54.3 | HIP 52843 | 10.38 |
| 2026-05-25 12:00 | 10:47:46.08 | -41:15:51.1 | HIP 52843 | 6.16 |
| 2026-05-26 00:00 | 10:47:38.68 | -41:05:53.9 | HIP 52843 | 13.08 |
| 2026-05-26 12:00 | 10:47:31.80 | -40:56:02.6 | HIP 52636 | 19.26 |
| 2026-05-27 00:00 | 10:47:25.43 | -40:46:17.1 | HIP 52636 | 21.64 |
| 2026-05-27 12:00 | 10:47:19.55 | -40:36:37.5 | HIP 52636 | 27.53 |
| 2026-05-28 00:00 | 10:47:14.17 | -40:27:03.8 | HIP 52583 | 26.53 |
| 2026-05-28 12:00 | 10:47:09.26 | -40:17:35.9 | HIP 52583 | 23.10 |
| 2026-05-29 00:00 | 10:47:04.82 | -40:08:13.8 | HIP 52779 | 19.85 |
| 2026-05-29 12:00 | 10:47:00.84 | -39:58:57.4 | HIP 52779 | 11.29 |
| 2026-05-30 00:00 | 10:46:57.31 | -39:49:46.9 | HIP 52779 | 5.77 |
| 2026-05-30 12:00 | 10:46:54.22 | -39:40:42.0 | HIP 52779 | 10.29 |
| 2026-05-31 00:00 | 10:46:51.57 | -39:31:42.9 | HIP 52807 | 16.42 |
| 2026-05-31 12:00 | 10:46:49.35 | -39:22:49.5 | HIP 52807 | 24.16 |
| 2026-06-01 00:00 | 10:46:47.54 | -39:14:01.7 | HIP 52589 | 28.29 |
| 2026-06-01 12:00 | 10:46:46.15 | -39:05:19.6 | HIP 52589 | 22.19 |
| 2026-06-02 00:00 | 10:46:45.15 | -38:56:43.1 | HIP 52589 | 18.43 |