C/1996 B2 (Hyakutake)
メタデータ
| 項目 | 値 |
|---|---|
| Designation | C/1996 B2 (Hyakutake) |
| Type | C |
| Perihelion (tp_cal, UTC) | 1996-05-01T09:27:34.128000Z |
| Orbit solution date (soln_date, UTC) | 2021-04-15T23:29:47Z |
| Obs used | 977 |
| NEO | - |
| M1 | 7.400 |
| K1 | 10.750 |
| PC | 0.030 |
オスキュレーティング軌道要素
| 項目 | 値 |
|---|---|
| Epoch (epoch_cal, TDB) | 1996-03-15.0000000 |
| e | 0.99989165 |
| q (au) | 0.230224 |
| a (au) | 2124.755444 |
| i (deg) | 124.922049 |
| Ω (om, deg) | 188.045132 |
| ω (w, deg) | 130.175121 |
| M (ma, deg) | 359.999523 |
等級
散乱 + 全体線形
$$ M_a = (5.511 + 2.906\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
モデル定数
| 項目 | 値 |
|---|---|
| H0 | 5.511 |
| n | 2.906 |
| gf | 0.800 |
| gb | -0.500 |
| k | 0.874 |
| δ90 | 1.000 |
| 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 |
|---|---|---|---|
| 1996-01-01 | 1996-02-10 | +46.8100 | -11.719 |
| 1996-02-10 | 1996-03-29 | +3.1700 | -0.159 |
| 1996-03-29 | 1996-05-01 | -0.2626 | -0.007 |
| 1996-05-01 | 1996-05-13 | +8.4125 | +3.278 |
| 1996-05-13 | 1996-06-16 | -1.7779 | -0.507 |
| 1996-06-16 | 1996-07-06 | +2.2007 | -0.648 |
| 1996-07-06 | 1996-08-06 | +6.4216 | -1.738 |
| 1996-08-06 | 1996-09-19 | +8.0209 | -2.381 |
| 1996-09-19 | 1996-10-24 | +58.8211 | -24.904 |
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 | 13:53:24.87 | -58:54:55.7 | HIP 67748 | 12.00 |
| 2026-02-03 12:00 | 13:53:23.92 | -58:55:17.4 | HIP 67748 | 11.62 |
| 2026-02-04 00:00 | 13:53:22.93 | -58:55:39.1 | HIP 67748 | 11.24 |
| 2026-02-04 12:00 | 13:53:21.90 | -58:56:00.6 | HIP 67748 | 10.86 |
| 2026-02-05 00:00 | 13:53:20.84 | -58:56:22.0 | HIP 67748 | 10.48 |
| 2026-02-05 12:00 | 13:53:19.75 | -58:56:43.2 | HIP 67748 | 10.10 |
| 2026-02-06 00:00 | 13:53:18.62 | -58:57:04.4 | HIP 67748 | 9.72 |
| 2026-02-06 12:00 | 13:53:17.46 | -58:57:25.4 | HIP 67748 | 9.34 |
| 2026-02-07 00:00 | 13:53:16.26 | -58:57:46.3 | HIP 67748 | 8.96 |
| 2026-02-07 12:00 | 13:53:15.03 | -58:58:07.1 | HIP 67748 | 8.58 |
| 2026-02-08 00:00 | 13:53:13.77 | -58:58:27.7 | HIP 67748 | 8.20 |
| 2026-02-08 12:00 | 13:53:12.47 | -58:58:48.3 | HIP 67748 | 7.82 |
| 2026-02-09 00:00 | 13:53:11.13 | -58:59:08.6 | HIP 67748 | 7.44 |
| 2026-02-09 12:00 | 13:53:09.77 | -58:59:28.9 | HIP 67748 | 7.06 |
| 2026-02-10 00:00 | 13:53:08.36 | -58:59:49.0 | HIP 67748 | 6.68 |
| 2026-02-10 12:00 | 13:53:06.93 | -59:00:09.0 | HIP 67748 | 6.29 |
| 2026-02-11 00:00 | 13:53:05.46 | -59:00:28.8 | HIP 67748 | 5.91 |
| 2026-02-11 12:00 | 13:53:03.96 | -59:00:48.5 | HIP 67748 | 5.53 |
| 2026-02-12 00:00 | 13:53:02.42 | -59:01:08.1 | HIP 67748 | 5.15 |
| 2026-02-12 12:00 | 13:53:00.85 | -59:01:27.5 | HIP 67748 | 4.77 |
| 2026-02-13 00:00 | 13:52:59.24 | -59:01:46.8 | HIP 67748 | 4.40 |
| 2026-02-13 12:00 | 13:52:57.60 | -59:02:05.9 | HIP 67748 | 4.02 |
| 2026-02-14 00:00 | 13:52:55.93 | -59:02:24.9 | HIP 67748 | 3.64 |
| 2026-02-14 12:00 | 13:52:54.23 | -59:02:43.7 | HIP 67748 | 3.27 |
| 2026-02-15 00:00 | 13:52:52.49 | -59:03:02.4 | HIP 67748 | 2.90 |
| 2026-02-15 12:00 | 13:52:50.72 | -59:03:20.9 | HIP 67748 | 2.53 |
| 2026-02-16 00:00 | 13:52:48.92 | -59:03:39.2 | HIP 67748 | 2.18 |
| 2026-02-16 12:00 | 13:52:47.08 | -59:03:57.4 | HIP 67748 | 1.83 |
| 2026-02-17 00:00 | 13:52:45.21 | -59:04:15.5 | HIP 67748 | 1.51 |
| 2026-02-17 12:00 | 13:52:43.31 | -59:04:33.4 | HIP 67748 | 1.22 |
| 2026-02-18 00:00 | 13:52:41.38 | -59:04:51.1 | HIP 67748 | 1.01 |
| 2026-02-18 12:00 | 13:52:39.41 | -59:05:08.7 | HIP 67748 | 0.93 |
| 2026-02-19 00:00 | 13:52:37.42 | -59:05:26.1 | HIP 67748 | 1.00 |
| 2026-02-19 12:00 | 13:52:35.39 | -59:05:43.3 | HIP 67748 | 1.21 |
| 2026-02-20 00:00 | 13:52:33.33 | -59:06:00.3 | HIP 67748 | 1.49 |
| 2026-02-20 12:00 | 13:52:31.23 | -59:06:17.2 | HIP 67748 | 1.82 |
| 2026-02-21 00:00 | 13:52:29.11 | -59:06:33.9 | HIP 67748 | 2.16 |
| 2026-02-21 12:00 | 13:52:26.95 | -59:06:50.5 | HIP 67748 | 2.53 |
| 2026-02-22 00:00 | 13:52:24.77 | -59:07:06.9 | HIP 67748 | 2.90 |
| 2026-02-22 12:00 | 13:52:22.55 | -59:07:23.1 | HIP 67748 | 3.28 |
| 2026-02-23 00:00 | 13:52:20.30 | -59:07:39.1 | HIP 67748 | 3.66 |
| 2026-02-23 12:00 | 13:52:18.03 | -59:07:54.9 | HIP 67748 | 4.05 |
| 2026-02-24 00:00 | 13:52:15.72 | -59:08:10.6 | HIP 67748 | 4.44 |