C/1989 A3 (Bradfield)
メタデータ
| 項目 |
値 |
| Designation |
C/1989 A3 (Bradfield) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1988-12-05T05:51:56.764800Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:36Z |
| Obs used |
23 |
| NEO |
Yes |
| M1 |
- |
| K1 |
- |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1989-01-25.0000000 |
| e |
0.97809250 |
| q (au) |
0.420517 |
| a (au) |
19.195134 |
| i (deg) |
83.059274 |
| Ω (om, deg) |
28.437814 |
| ω (w, deg) |
194.769984 |
| M (ma, deg) |
0.594842 |
等級
散乱 + 全体線形
$$
M_a = (10.535 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.535 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-1.000 |
| k |
0.987 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
01:25:36.84 |
+23:32:52.6 |
HIP 6669 |
2.20 |
| 2026-02-03 12:00 |
01:25:37.94 |
+23:32:48.5 |
HIP 6669 |
2.18 |
| 2026-02-04 00:00 |
01:25:39.07 |
+23:32:44.5 |
HIP 6669 |
2.19 |
| 2026-02-04 12:00 |
01:25:40.22 |
+23:32:40.7 |
HIP 6669 |
2.24 |
| 2026-02-05 00:00 |
01:25:41.40 |
+23:32:37.1 |
HIP 6669 |
2.33 |
| 2026-02-05 12:00 |
01:25:42.60 |
+23:32:33.7 |
HIP 6669 |
2.45 |
| 2026-02-06 00:00 |
01:25:43.83 |
+23:32:30.4 |
HIP 6669 |
2.61 |
| 2026-02-06 12:00 |
01:25:45.09 |
+23:32:27.3 |
HIP 6669 |
2.79 |
| 2026-02-07 00:00 |
01:25:46.37 |
+23:32:24.4 |
HIP 6669 |
2.99 |
| 2026-02-07 12:00 |
01:25:47.67 |
+23:32:21.7 |
HIP 6669 |
3.22 |
| 2026-02-08 00:00 |
01:25:49.00 |
+23:32:19.1 |
HIP 6669 |
3.46 |
| 2026-02-08 12:00 |
01:25:50.35 |
+23:32:16.8 |
HIP 6669 |
3.72 |
| 2026-02-09 00:00 |
01:25:51.73 |
+23:32:14.6 |
HIP 6669 |
4.00 |
| 2026-02-09 12:00 |
01:25:53.13 |
+23:32:12.6 |
HIP 6669 |
4.28 |
| 2026-02-10 00:00 |
01:25:54.56 |
+23:32:10.7 |
HIP 6669 |
4.58 |
| 2026-02-10 12:00 |
01:25:56.01 |
+23:32:09.1 |
HIP 6669 |
4.89 |
| 2026-02-11 00:00 |
01:25:57.48 |
+23:32:07.6 |
HIP 6669 |
5.20 |
| 2026-02-11 12:00 |
01:25:58.98 |
+23:32:06.3 |
HIP 6669 |
5.53 |
| 2026-02-12 00:00 |
01:26:00.50 |
+23:32:05.2 |
HIP 6669 |
5.86 |
| 2026-02-12 12:00 |
01:26:02.05 |
+23:32:04.3 |
HIP 6669 |
6.20 |
| 2026-02-13 00:00 |
01:26:03.62 |
+23:32:03.5 |
HIP 6669 |
6.55 |
| 2026-02-13 12:00 |
01:26:05.21 |
+23:32:03.0 |
HIP 6669 |
6.91 |
| 2026-02-14 00:00 |
01:26:06.83 |
+23:32:02.6 |
HIP 6669 |
7.27 |
| 2026-02-14 12:00 |
01:26:08.47 |
+23:32:02.3 |
HIP 6669 |
7.64 |
| 2026-02-15 00:00 |
01:26:10.13 |
+23:32:02.3 |
HIP 6669 |
8.02 |
| 2026-02-15 12:00 |
01:26:11.82 |
+23:32:02.5 |
HIP 6669 |
8.40 |
| 2026-02-16 00:00 |
01:26:13.53 |
+23:32:02.8 |
HIP 6669 |
8.79 |
| 2026-02-16 12:00 |
01:26:15.26 |
+23:32:03.3 |
HIP 6669 |
9.18 |
| 2026-02-17 00:00 |
01:26:17.01 |
+23:32:04.0 |
HIP 6669 |
9.58 |
| 2026-02-17 12:00 |
01:26:18.79 |
+23:32:04.8 |
HIP 6669 |
9.98 |
| 2026-02-18 00:00 |
01:26:20.58 |
+23:32:05.9 |
HIP 6669 |
10.39 |
| 2026-02-18 12:00 |
01:26:22.40 |
+23:32:07.1 |
HIP 6669 |
10.81 |
| 2026-02-19 00:00 |
01:26:24.24 |
+23:32:08.5 |
HIP 6669 |
11.23 |
| 2026-02-19 12:00 |
01:26:26.11 |
+23:32:10.1 |
HIP 6669 |
11.66 |
| 2026-02-20 00:00 |
01:26:27.99 |
+23:32:11.8 |
HIP 6669 |
12.09 |
| 2026-02-20 12:00 |
01:26:29.90 |
+23:32:13.8 |
HIP 6669 |
12.53 |
| 2026-02-21 00:00 |
01:26:31.83 |
+23:32:15.9 |
HIP 6669 |
12.97 |
| 2026-02-21 12:00 |
01:26:33.77 |
+23:32:18.2 |
HIP 6669 |
13.42 |
| 2026-02-22 00:00 |
01:26:35.74 |
+23:32:20.6 |
HIP 6669 |
13.87 |
| 2026-02-22 12:00 |
01:26:37.73 |
+23:32:23.3 |
HIP 6741 |
13.96 |
| 2026-02-23 00:00 |
01:26:39.74 |
+23:32:26.1 |
HIP 6741 |
13.94 |
| 2026-02-23 12:00 |
01:26:41.77 |
+23:32:29.1 |
HIP 6741 |
13.94 |
| 2026-02-24 00:00 |
01:26:43.82 |
+23:32:32.2 |
HIP 6741 |
13.95 |