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) |
| 2026-06-01 00:00 |
01:35:40.98 |
+24:21:45.0 |
HIP 7487 |
13.24 |
| 2026-06-01 12:00 |
01:35:43.19 |
+24:22:05.5 |
HIP 7487 |
13.10 |
| 2026-06-02 00:00 |
01:35:45.39 |
+24:22:26.0 |
HIP 7487 |
12.99 |
| 2026-06-02 12:00 |
01:35:47.57 |
+24:22:46.5 |
HIP 7487 |
12.91 |
| 2026-06-03 00:00 |
01:35:49.72 |
+24:23:07.0 |
HIP 7487 |
12.86 |
| 2026-06-03 12:00 |
01:35:51.87 |
+24:23:27.4 |
HIP 7487 |
12.84 |
| 2026-06-04 00:00 |
01:35:53.99 |
+24:23:47.8 |
HIP 7487 |
12.85 |
| 2026-06-04 12:00 |
01:35:56.09 |
+24:24:08.1 |
HIP 7487 |
12.89 |
| 2026-06-05 00:00 |
01:35:58.18 |
+24:24:28.5 |
HIP 7487 |
12.95 |
| 2026-06-05 12:00 |
01:36:00.25 |
+24:24:48.8 |
HIP 7487 |
13.05 |
| 2026-06-06 00:00 |
01:36:02.29 |
+24:25:09.0 |
HIP 7487 |
13.17 |
| 2026-06-06 12:00 |
01:36:04.32 |
+24:25:29.3 |
HIP 7487 |
13.31 |
| 2026-06-07 00:00 |
01:36:06.33 |
+24:25:49.5 |
HIP 7487 |
13.48 |
| 2026-06-07 12:00 |
01:36:08.32 |
+24:26:09.6 |
HIP 7487 |
13.67 |
| 2026-06-08 00:00 |
01:36:10.29 |
+24:26:29.7 |
HIP 7487 |
13.88 |
| 2026-06-08 12:00 |
01:36:12.24 |
+24:26:49.8 |
HIP 7487 |
14.11 |
| 2026-06-09 00:00 |
01:36:14.18 |
+24:27:09.9 |
HIP 7487 |
14.35 |
| 2026-06-09 12:00 |
01:36:16.09 |
+24:27:29.9 |
HIP 7487 |
14.62 |
| 2026-06-10 00:00 |
01:36:17.98 |
+24:27:49.8 |
HIP 7487 |
14.90 |
| 2026-06-10 12:00 |
01:36:19.85 |
+24:28:09.7 |
HIP 7487 |
15.19 |
| 2026-06-11 00:00 |
01:36:21.70 |
+24:28:29.6 |
HIP 7487 |
15.50 |
| 2026-06-11 12:00 |
01:36:23.53 |
+24:28:49.4 |
HIP 7487 |
15.81 |
| 2026-06-12 00:00 |
01:36:25.34 |
+24:29:09.2 |
HIP 7487 |
16.14 |
| 2026-06-12 12:00 |
01:36:27.13 |
+24:29:28.9 |
HIP 7487 |
16.48 |
| 2026-06-13 00:00 |
01:36:28.90 |
+24:29:48.5 |
HIP 7487 |
16.83 |
| 2026-06-13 12:00 |
01:36:30.64 |
+24:30:08.2 |
HIP 7487 |
17.18 |
| 2026-06-14 00:00 |
01:36:32.37 |
+24:30:27.7 |
HIP 7487 |
17.54 |
| 2026-06-14 12:00 |
01:36:34.07 |
+24:30:47.2 |
HIP 7487 |
17.90 |
| 2026-06-15 00:00 |
01:36:35.75 |
+24:31:06.7 |
HIP 7487 |
18.28 |
| 2026-06-15 12:00 |
01:36:37.41 |
+24:31:26.0 |
HIP 7487 |
18.65 |
| 2026-06-16 00:00 |
01:36:39.05 |
+24:31:45.4 |
HIP 7487 |
19.03 |
| 2026-06-16 12:00 |
01:36:40.67 |
+24:32:04.6 |
HIP 7487 |
19.41 |
| 2026-06-17 00:00 |
01:36:42.26 |
+24:32:23.8 |
HIP 7487 |
19.80 |
| 2026-06-17 12:00 |
01:36:43.83 |
+24:32:43.0 |
HIP 7487 |
20.18 |
| 2026-06-18 00:00 |
01:36:45.38 |
+24:33:02.1 |
HIP 7487 |
20.57 |
| 2026-06-18 12:00 |
01:36:46.91 |
+24:33:21.1 |
HIP 7487 |
20.96 |
| 2026-06-19 00:00 |
01:36:48.41 |
+24:33:40.0 |
HIP 7487 |
21.35 |
| 2026-06-19 12:00 |
01:36:49.89 |
+24:33:58.9 |
HIP 7487 |
21.74 |
| 2026-06-20 00:00 |
01:36:51.35 |
+24:34:17.7 |
HIP 7487 |
22.13 |
| 2026-06-20 12:00 |
01:36:52.79 |
+24:34:36.4 |
HIP 7487 |
22.53 |
| 2026-06-21 00:00 |
01:36:54.20 |
+24:34:55.1 |
HIP 7487 |
22.92 |
| 2026-06-21 12:00 |
01:36:55.59 |
+24:35:13.7 |
HIP 7487 |
23.31 |
| 2026-06-22 00:00 |
01:36:56.96 |
+24:35:32.2 |
HIP 7487 |
23.70 |