メタデータ
| 項目 |
値 |
| Designation |
C/1995 Y1 (Hyakutake) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1996-02-24T06:53:53.528640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:47Z |
| Obs used |
259 |
| NEO |
- |
| M1 |
9.900 |
| K1 |
15.000 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1996-02-24.0000000 |
| e |
1.00026947 |
| q (au) |
1.054617 |
| a (au) |
-3913.664483 |
| i (deg) |
54.466072 |
| Ω (om, deg) |
195.761478 |
| ω (w, deg) |
46.348701 |
| M (ma, deg) |
-0.000001 |
等級
散乱 + 全体線形
$$
M_a = (6.861 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
6.861 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.998 |
| 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 |
| 1995-12-27 |
1996-01-15 |
-32.9619 |
+4.433 |
| 1996-01-15 |
1996-02-24 |
+5.8871 |
-0.300 |
| 1996-02-24 |
1996-07-18 |
+2.0313 |
-0.181 |
| 1996-07-18 |
1996-10-05 |
+7.6754 |
-1.742 |
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) |
| 2026-06-01 00:00 |
02:43:03.52 |
-09:13:26.5 |
HIP 12760 |
14.12 |
| 2026-06-01 12:00 |
02:43:05.43 |
-09:13:25.3 |
HIP 12760 |
13.66 |
| 2026-06-02 00:00 |
02:43:07.33 |
-09:13:24.2 |
HIP 12760 |
13.19 |
| 2026-06-02 12:00 |
02:43:09.22 |
-09:13:23.2 |
HIP 12760 |
12.74 |
| 2026-06-03 00:00 |
02:43:11.10 |
-09:13:22.4 |
HIP 12760 |
12.28 |
| 2026-06-03 12:00 |
02:43:12.97 |
-09:13:21.7 |
HIP 12760 |
11.83 |
| 2026-06-04 00:00 |
02:43:14.84 |
-09:13:21.2 |
HIP 12760 |
11.38 |
| 2026-06-04 12:00 |
02:43:16.70 |
-09:13:20.8 |
HIP 12760 |
10.93 |
| 2026-06-05 00:00 |
02:43:18.54 |
-09:13:20.5 |
HIP 12760 |
10.49 |
| 2026-06-05 12:00 |
02:43:20.38 |
-09:13:20.3 |
HIP 12760 |
10.05 |
| 2026-06-06 00:00 |
02:43:22.21 |
-09:13:20.3 |
HIP 12760 |
9.62 |
| 2026-06-06 12:00 |
02:43:24.04 |
-09:13:20.5 |
HIP 12760 |
9.19 |
| 2026-06-07 00:00 |
02:43:25.85 |
-09:13:20.8 |
HIP 12760 |
8.76 |
| 2026-06-07 12:00 |
02:43:27.65 |
-09:13:21.2 |
HIP 12760 |
8.34 |
| 2026-06-08 00:00 |
02:43:29.45 |
-09:13:21.7 |
HIP 12760 |
7.93 |
| 2026-06-08 12:00 |
02:43:31.23 |
-09:13:22.4 |
HIP 12760 |
7.52 |
| 2026-06-09 00:00 |
02:43:33.01 |
-09:13:23.2 |
HIP 12760 |
7.12 |
| 2026-06-09 12:00 |
02:43:34.77 |
-09:13:24.2 |
HIP 12760 |
6.73 |
| 2026-06-10 00:00 |
02:43:36.53 |
-09:13:25.3 |
HIP 12760 |
6.35 |
| 2026-06-10 12:00 |
02:43:38.28 |
-09:13:26.5 |
HIP 12760 |
5.97 |
| 2026-06-11 00:00 |
02:43:40.01 |
-09:13:27.9 |
HIP 12760 |
5.61 |
| 2026-06-11 12:00 |
02:43:41.74 |
-09:13:29.4 |
HIP 12760 |
5.26 |
| 2026-06-12 00:00 |
02:43:43.45 |
-09:13:31.0 |
HIP 12760 |
4.93 |
| 2026-06-12 12:00 |
02:43:45.16 |
-09:13:32.8 |
HIP 12760 |
4.62 |
| 2026-06-13 00:00 |
02:43:46.85 |
-09:13:34.8 |
HIP 12760 |
4.32 |
| 2026-06-13 12:00 |
02:43:48.54 |
-09:13:36.8 |
HIP 12760 |
4.06 |
| 2026-06-14 00:00 |
02:43:50.21 |
-09:13:39.0 |
HIP 12760 |
3.82 |
| 2026-06-14 12:00 |
02:43:51.87 |
-09:13:41.4 |
HIP 12760 |
3.62 |
| 2026-06-15 00:00 |
02:43:53.52 |
-09:13:43.8 |
HIP 12760 |
3.46 |
| 2026-06-15 12:00 |
02:43:55.16 |
-09:13:46.4 |
HIP 12760 |
3.35 |
| 2026-06-16 00:00 |
02:43:56.79 |
-09:13:49.2 |
HIP 12760 |
3.28 |
| 2026-06-16 12:00 |
02:43:58.41 |
-09:13:52.1 |
HIP 12760 |
3.27 |
| 2026-06-17 00:00 |
02:44:00.02 |
-09:13:55.1 |
HIP 12760 |
3.31 |
| 2026-06-17 12:00 |
02:44:01.61 |
-09:13:58.3 |
HIP 12760 |
3.40 |
| 2026-06-18 00:00 |
02:44:03.19 |
-09:14:01.6 |
HIP 12760 |
3.53 |
| 2026-06-18 12:00 |
02:44:04.76 |
-09:14:05.0 |
HIP 12760 |
3.70 |
| 2026-06-19 00:00 |
02:44:06.32 |
-09:14:08.6 |
HIP 12760 |
3.91 |
| 2026-06-19 12:00 |
02:44:07.87 |
-09:14:12.3 |
HIP 12760 |
4.14 |
| 2026-06-20 00:00 |
02:44:09.40 |
-09:14:16.1 |
HIP 12760 |
4.39 |
| 2026-06-20 12:00 |
02:44:10.92 |
-09:14:20.1 |
HIP 12760 |
4.66 |
| 2026-06-21 00:00 |
02:44:12.43 |
-09:14:24.2 |
HIP 12760 |
4.95 |
| 2026-06-21 12:00 |
02:44:13.93 |
-09:14:28.5 |
HIP 12760 |
5.24 |
| 2026-06-22 00:00 |
02:44:15.42 |
-09:14:32.8 |
HIP 12760 |
5.55 |