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 | 1996-02-19 | +29.8208 | -6.480 |
| 1996-02-19 | 1996-03-29 | +2.2342 | -0.120 |
| 1996-03-29 | 1996-05-01 | -0.1997 | +0.012 |
| 1996-05-01 | 1996-05-17 | +4.8585 | +1.527 |
| 1996-05-17 | 1996-06-11 | -2.2356 | -0.537 |
| 1996-06-11 | 1996-07-06 | +3.6146 | -0.826 |
| 1996-07-06 | 1996-08-01 | +3.0246 | -0.925 |
| 1996-08-01 | 1996-10-24 | +15.0784 | -4.852 |
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) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 13:42:58.78 | -59:05:55.2 | HIP 66913 | 5.85 |
| 2026-05-12 12:00 | 13:42:55.07 | -59:05:38.0 | HIP 66913 | 5.47 |
| 2026-05-13 00:00 | 13:42:51.38 | -59:05:20.6 | HIP 66913 | 5.11 |
| 2026-05-13 12:00 | 13:42:47.70 | -59:05:03.0 | HIP 66913 | 4.79 |
| 2026-05-14 00:00 | 13:42:44.04 | -59:04:45.3 | HIP 66913 | 4.51 |
| 2026-05-14 12:00 | 13:42:40.39 | -59:04:27.3 | HIP 66913 | 4.29 |
| 2026-05-15 00:00 | 13:42:36.77 | -59:04:09.3 | HIP 66913 | 4.12 |
| 2026-05-15 12:00 | 13:42:33.15 | -59:03:51.0 | HIP 66913 | 4.02 |
| 2026-05-16 00:00 | 13:42:29.56 | -59:03:32.6 | HIP 66913 | 4.00 |
| 2026-05-16 12:00 | 13:42:25.98 | -59:03:14.0 | HIP 66913 | 4.04 |
| 2026-05-17 00:00 | 13:42:22.41 | -59:02:55.3 | HIP 66913 | 4.16 |
| 2026-05-17 12:00 | 13:42:18.87 | -59:02:36.4 | HIP 66913 | 4.34 |
| 2026-05-18 00:00 | 13:42:15.34 | -59:02:17.3 | HIP 66880 | 4.13 |
| 2026-05-18 12:00 | 13:42:11.83 | -59:01:58.1 | HIP 66880 | 3.97 |
| 2026-05-19 00:00 | 13:42:08.34 | -59:01:38.8 | HIP 66880 | 3.88 |
| 2026-05-19 12:00 | 13:42:04.87 | -59:01:19.3 | HIP 66880 | 3.87 |
| 2026-05-20 00:00 | 13:42:01.42 | -59:00:59.6 | HIP 66880 | 3.93 |
| 2026-05-20 12:00 | 13:41:57.98 | -59:00:39.8 | HIP 66880 | 4.06 |
| 2026-05-21 00:00 | 13:41:54.57 | -59:00:19.8 | HIP 66880 | 4.25 |
| 2026-05-21 12:00 | 13:41:51.17 | -58:59:59.7 | HIP 66880 | 4.51 |
| 2026-05-22 00:00 | 13:41:47.80 | -58:59:39.5 | HIP 66880 | 4.80 |
| 2026-05-22 12:00 | 13:41:44.44 | -58:59:19.1 | HIP 66880 | 5.14 |
| 2026-05-23 00:00 | 13:41:41.11 | -58:58:58.6 | HIP 66880 | 5.51 |
| 2026-05-23 12:00 | 13:41:37.79 | -58:58:37.9 | HIP 66880 | 5.91 |
| 2026-05-24 00:00 | 13:41:34.50 | -58:58:17.1 | HIP 66880 | 6.32 |
| 2026-05-24 12:00 | 13:41:31.23 | -58:57:56.1 | HIP 66880 | 6.75 |
| 2026-05-25 00:00 | 13:41:27.98 | -58:57:35.1 | HIP 66880 | 7.20 |
| 2026-05-25 12:00 | 13:41:24.75 | -58:57:13.9 | HIP 66880 | 7.65 |
| 2026-05-26 00:00 | 13:41:21.54 | -58:56:52.5 | HIP 66880 | 8.12 |
| 2026-05-26 12:00 | 13:41:18.35 | -58:56:31.1 | HIP 66880 | 8.59 |
| 2026-05-27 00:00 | 13:41:15.19 | -58:56:09.5 | HIP 66880 | 9.07 |
| 2026-05-27 12:00 | 13:41:12.05 | -58:55:47.8 | HIP 66880 | 9.55 |
| 2026-05-28 00:00 | 13:41:08.93 | -58:55:26.0 | HIP 66880 | 10.04 |
| 2026-05-28 12:00 | 13:41:05.83 | -58:55:04.0 | HIP 66880 | 10.53 |
| 2026-05-29 00:00 | 13:41:02.76 | -58:54:41.9 | HIP 66849 | 10.62 |
| 2026-05-29 12:00 | 13:40:59.71 | -58:54:19.8 | HIP 66849 | 10.66 |
| 2026-05-30 00:00 | 13:40:56.68 | -58:53:57.5 | HIP 66849 | 10.72 |
| 2026-05-30 12:00 | 13:40:53.68 | -58:53:35.0 | HIP 66849 | 10.80 |
| 2026-05-31 00:00 | 13:40:50.70 | -58:53:12.5 | HIP 66849 | 10.90 |
| 2026-05-31 12:00 | 13:40:47.74 | -58:52:49.9 | HIP 66849 | 11.03 |
| 2026-06-01 00:00 | 13:40:44.81 | -58:52:27.1 | HIP 66849 | 11.17 |
| 2026-06-01 12:00 | 13:40:41.90 | -58:52:04.3 | HIP 66849 | 11.34 |
| 2026-06-02 00:00 | 13:40:39.02 | -58:51:41.3 | HIP 66849 | 11.53 |