C/2026 A2 (Bok)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/2026 A2 (Bok) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2026-12-22T08:29:31.741440Z |
| Orbit solution date (soln_date, UTC) | 2026-10-01T14:42:11Z |
| Obs used | 1368 |
| NEO | - |
| M1 | 8.800 |
| K1 | 12.750 |
| PC | - |
| Discovery observation (MPC, UTC) | 2026-01-15T12:52:17.616000Z |
| Discovery magnitude (MPC) | 20.38 G |
| Discovery observatory (MPC) | V00 · Kitt Peak-Bok |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 2026-06-24.0000000 |
| e | 0.99763096 |
| q (au) | 1.937809 |
| a (au) | 817.972428 |
| i (deg) | 82.305771 |
| Ω (om, deg) | 206.588727 |
| ω (w, deg) | 155.936753 |
| M (ma, deg) | 359.992359 |
等級
散乱 + 全体線形
$$ M_a = (6.885 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 6.885 |
| n | 6.000 |
| gf | 1.000 |
| gb | -0.877 |
| k | 0.999 |
| 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 |
|---|---|---|---|
| 2026-01-15 | 2026-08-17 | -0.5337 | +0.232 |
| 2026-08-17 | 2026-10-01 | +10.4033 | -3.933 |
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) |
|---|---|---|---|---|
| 2026-09-25 00:00 | 17:37:50.22 | +70:27:05.4 | HIP 86421 | 13.93 |
| 2026-09-25 12:00 | 17:39:41.24 | +70:19:29.5 | HIP 86568 | 12.21 |
| 2026-09-26 00:00 | 17:41:32.92 | +70:11:47.3 | HIP 86568 | 16.07 |
| 2026-09-26 12:00 | 17:43:25.23 | +70:03:58.6 | HIP 86876 | 24.27 |
| 2026-09-27 00:00 | 17:45:18.16 | +69:56:03.4 | HIP 87051 | 14.88 |
| 2026-09-27 12:00 | 17:47:11.69 | +69:48:01.5 | HIP 87051 | 3.15 |
| 2026-09-28 00:00 | 17:49:05.80 | +69:39:52.9 | HIP 87051 | 11.05 |
| 2026-09-28 12:00 | 17:51:00.48 | +69:31:37.3 | HIP 87730 | 22.58 |
| 2026-09-29 00:00 | 17:52:55.71 | +69:23:14.7 | HIP 87703 | 14.26 |
| 2026-09-29 12:00 | 17:54:51.46 | +69:14:45.0 | HIP 87703 | 1.43 |
| 2026-09-30 00:00 | 17:56:47.74 | +69:06:08.1 | HIP 87703 | 12.59 |
| 2026-09-30 12:00 | 17:58:44.51 | +68:57:23.8 | HIP 88226 | 25.45 |
| 2026-10-01 00:00 | 18:00:41.76 | +68:48:32.0 | HIP 88226 | 13.51 |
| 2026-10-01 12:00 | 18:02:39.47 | +68:39:32.6 | HIP 88226 | 10.04 |
| 2026-10-02 00:00 | 18:04:37.63 | +68:30:25.6 | HIP 88226 | 20.40 |
| 2026-10-02 12:00 | 18:06:36.22 | +68:21:10.7 | HIP 88909 | 25.44 |
| 2026-10-03 00:00 | 18:08:35.22 | +68:11:47.9 | HIP 88909 | 12.65 |
| 2026-10-03 12:00 | 18:10:34.61 | +68:02:17.1 | HIP 88909 | 9.73 |
| 2026-10-04 00:00 | 18:12:34.38 | +67:52:38.1 | HIP 89011 | 15.53 |
| 2026-10-04 12:00 | 18:14:34.50 | +67:42:50.9 | HIP 89011 | 26.18 |
| 2026-10-05 00:00 | 18:16:34.97 | +67:32:55.3 | HIP 89807 | 19.03 |
| 2026-10-05 12:00 | 18:18:35.76 | +67:22:51.3 | HIP 89807 | 7.02 |
| 2026-10-06 00:00 | 18:20:36.86 | +67:12:38.8 | HIP 89742 | 13.83 |
| 2026-10-06 12:00 | 18:22:38.24 | +67:02:17.6 | HIP 89742 | 22.06 |
| 2026-10-07 00:00 | 18:24:39.90 | +66:51:47.7 | HIP 90462 | 17.83 |
| 2026-10-07 12:00 | 18:26:41.80 | +66:41:08.9 | HIP 90462 | 7.58 |
| 2026-10-08 00:00 | 18:28:43.94 | +66:30:21.1 | HIP 90462 | 17.80 |
| 2026-10-08 12:00 | 18:30:46.30 | +66:19:24.4 | HIP 90771 | 12.08 |
| 2026-10-09 00:00 | 18:32:48.85 | +66:08:18.5 | HIP 90771 | 9.96 |
| 2026-10-09 12:00 | 18:34:51.59 | +65:57:03.5 | HIP 90771 | 24.77 |
| 2026-10-10 00:00 | 18:36:54.48 | +65:45:39.1 | HIP 91196 | 16.89 |
| 2026-10-10 12:00 | 18:38:57.52 | +65:34:05.4 | HIP 91196 | 17.67 |
| 2026-10-11 00:00 | 18:41:00.69 | +65:22:22.2 | HIP 91196 | 30.67 |
| 2026-10-11 12:00 | 18:43:03.96 | +65:10:29.5 | HIP 91950 | 23.93 |
| 2026-10-12 00:00 | 18:45:07.32 | +64:58:27.2 | HIP 91950 | 10.43 |
| 2026-10-12 12:00 | 18:47:10.76 | +64:46:15.2 | HIP 91950 | 16.72 |
| 2026-10-13 00:00 | 18:49:14.25 | +64:33:53.5 | HIP 92362 | 5.92 |
| 2026-10-13 12:00 | 18:51:17.78 | +64:21:21.9 | HIP 92362 | 13.84 |
| 2026-10-14 00:00 | 18:53:21.33 | +64:08:40.4 | HIP 92848 | 26.05 |
| 2026-10-14 12:00 | 18:55:24.88 | +63:55:49.1 | HIP 93269 | 30.83 |
| 2026-10-15 00:00 | 18:57:28.42 | +63:42:47.7 | HIP 93143 | 18.00 |
| 2026-10-15 12:00 | 18:59:31.93 | +63:29:36.2 | HIP 93143 | 8.15 |
| 2026-10-16 00:00 | 19:01:35.39 | +63:16:14.6 | HIP 93241 | 20.60 |