メタデータ
| 項目 |
値 |
| Designation |
C/1984 A1 (Bradfield 1) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1983-12-27T19:07:03.864000Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:31Z |
| Obs used |
33 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1984-02-25.0000000 |
| e |
0.95231517 |
| q (au) |
1.357490 |
| a (au) |
28.467973 |
| i (deg) |
51.800566 |
| Ω (om, deg) |
356.858343 |
| ω (w, deg) |
219.164863 |
| M (ma, deg) |
0.384163 |
等級
散乱 + 全体線形
$$
M_a = (7.897 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
7.897 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
00:24:19.07 |
+29:29:36.4 |
HIP 1891 |
5.66 |
| 2026-03-26 12:00 |
00:24:21.68 |
+29:29:49.9 |
HIP 1891 |
6.21 |
| 2026-03-27 00:00 |
00:24:24.30 |
+29:30:03.5 |
HIP 1891 |
6.77 |
| 2026-03-27 12:00 |
00:24:26.91 |
+29:30:17.3 |
HIP 1891 |
7.34 |
| 2026-03-28 00:00 |
00:24:29.52 |
+29:30:31.3 |
HIP 1891 |
7.91 |
| 2026-03-28 12:00 |
00:24:32.14 |
+29:30:45.3 |
HIP 1891 |
8.49 |
| 2026-03-29 00:00 |
00:24:34.75 |
+29:30:59.6 |
HIP 1891 |
9.08 |
| 2026-03-29 12:00 |
00:24:37.36 |
+29:31:13.9 |
HIP 1891 |
9.67 |
| 2026-03-30 00:00 |
00:24:39.97 |
+29:31:28.4 |
HIP 1891 |
10.26 |
| 2026-03-30 12:00 |
00:24:42.58 |
+29:31:43.0 |
HIP 1891 |
10.86 |
| 2026-03-31 00:00 |
00:24:45.19 |
+29:31:57.7 |
HIP 1891 |
11.45 |
| 2026-03-31 12:00 |
00:24:47.80 |
+29:32:12.6 |
HIP 1891 |
12.05 |
| 2026-04-01 00:00 |
00:24:50.41 |
+29:32:27.6 |
HIP 1891 |
12.66 |
| 2026-04-01 12:00 |
00:24:53.01 |
+29:32:42.8 |
HIP 1891 |
13.26 |
| 2026-04-02 00:00 |
00:24:55.61 |
+29:32:58.0 |
HIP 1891 |
13.87 |
| 2026-04-02 12:00 |
00:24:58.22 |
+29:33:13.4 |
HIP 1891 |
14.47 |
| 2026-04-03 00:00 |
00:25:00.81 |
+29:33:28.9 |
HIP 1891 |
15.08 |
| 2026-04-03 12:00 |
00:25:03.41 |
+29:33:44.6 |
HIP 1891 |
15.69 |
| 2026-04-04 00:00 |
00:25:06.01 |
+29:34:00.4 |
HIP 1891 |
16.30 |
| 2026-04-04 12:00 |
00:25:08.60 |
+29:34:16.2 |
HIP 1980 |
16.58 |
| 2026-04-05 00:00 |
00:25:11.19 |
+29:34:32.3 |
HIP 1980 |
16.36 |
| 2026-04-05 12:00 |
00:25:13.77 |
+29:34:48.4 |
HIP 1980 |
16.15 |
| 2026-04-06 00:00 |
00:25:16.36 |
+29:35:04.7 |
HIP 1980 |
15.96 |
| 2026-04-06 12:00 |
00:25:18.94 |
+29:35:21.0 |
HIP 1980 |
15.79 |
| 2026-04-07 00:00 |
00:25:21.51 |
+29:35:37.5 |
HIP 1980 |
15.64 |
| 2026-04-07 12:00 |
00:25:24.09 |
+29:35:54.1 |
HIP 1980 |
15.51 |
| 2026-04-08 00:00 |
00:25:26.66 |
+29:36:10.9 |
HIP 1980 |
15.40 |
| 2026-04-08 12:00 |
00:25:29.22 |
+29:36:27.7 |
HIP 1980 |
15.32 |
| 2026-04-09 00:00 |
00:25:31.78 |
+29:36:44.7 |
HIP 1980 |
15.26 |
| 2026-04-09 12:00 |
00:25:34.34 |
+29:37:01.7 |
HIP 1980 |
15.22 |
| 2026-04-10 00:00 |
00:25:36.89 |
+29:37:18.9 |
HIP 1980 |
15.21 |
| 2026-04-10 12:00 |
00:25:39.44 |
+29:37:36.2 |
HIP 1980 |
15.22 |
| 2026-04-11 00:00 |
00:25:41.98 |
+29:37:53.6 |
HIP 1980 |
15.25 |
| 2026-04-11 12:00 |
00:25:44.52 |
+29:38:11.1 |
HIP 1980 |
15.31 |
| 2026-04-12 00:00 |
00:25:47.05 |
+29:38:28.8 |
HIP 1980 |
15.39 |
| 2026-04-12 12:00 |
00:25:49.58 |
+29:38:46.5 |
HIP 1980 |
15.49 |
| 2026-04-13 00:00 |
00:25:52.10 |
+29:39:04.3 |
HIP 1980 |
15.62 |
| 2026-04-13 12:00 |
00:25:54.62 |
+29:39:22.3 |
HIP 1980 |
15.76 |
| 2026-04-14 00:00 |
00:25:57.13 |
+29:39:40.3 |
HIP 1980 |
15.93 |
| 2026-04-14 12:00 |
00:25:59.64 |
+29:39:58.5 |
HIP 1980 |
16.12 |
| 2026-04-15 00:00 |
00:26:02.14 |
+29:40:16.7 |
HIP 1980 |
16.32 |
| 2026-04-15 12:00 |
00:26:04.63 |
+29:40:35.0 |
HIP 1980 |
16.55 |
| 2026-04-16 00:00 |
00:26:07.11 |
+29:40:53.5 |
HIP 1980 |
16.79 |