メタデータ
| 項目 |
値 |
| Designation |
C/1979 Y1 (Bradfield) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1979-12-21T14:38:01.069440Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:29Z |
| Obs used |
127 |
| NEO |
- |
| M1 |
8.500 |
| K1 |
14.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1980-01-25.0000000 |
| e |
0.98803814 |
| q (au) |
0.545301 |
| a (au) |
45.586646 |
| i (deg) |
148.602533 |
| Ω (om, deg) |
103.215535 |
| ω (w, deg) |
257.609730 |
| M (ma, deg) |
0.110124 |
等級
散乱 + 全体線形
$$
M_a = (8.331 + 4.383\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
8.331 |
| n |
4.383 |
| gf |
0.800 |
| gb |
-1.000 |
| k |
0.800 |
| 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 |
| 1979-12-26 |
1980-01-04 |
+1.4679 |
-0.064 |
| 1980-01-04 |
1980-01-25 |
+5.5414 |
+0.963 |
| 1980-01-25 |
1980-03-02 |
-4.9082 |
+0.307 |
| 1980-03-02 |
1980-03-17 |
-4.0819 |
-0.038 |
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) |
| 2026-09-20 00:00 |
01:22:51.19 |
+41:12:25.6 |
HIP 6341 |
21.54 |
| 2026-09-20 12:00 |
01:22:48.91 |
+41:12:23.6 |
HIP 6341 |
21.21 |
| 2026-09-21 00:00 |
01:22:46.62 |
+41:12:21.4 |
HIP 6341 |
20.88 |
| 2026-09-21 12:00 |
01:22:44.32 |
+41:12:19.1 |
HIP 6341 |
20.55 |
| 2026-09-22 00:00 |
01:22:42.01 |
+41:12:16.6 |
HIP 6341 |
20.22 |
| 2026-09-22 12:00 |
01:22:39.69 |
+41:12:13.9 |
HIP 6341 |
19.89 |
| 2026-09-23 00:00 |
01:22:37.37 |
+41:12:11.1 |
HIP 6341 |
19.56 |
| 2026-09-23 12:00 |
01:22:35.03 |
+41:12:08.1 |
HIP 6341 |
19.24 |
| 2026-09-24 00:00 |
01:22:32.69 |
+41:12:04.9 |
HIP 6341 |
18.92 |
| 2026-09-24 12:00 |
01:22:30.34 |
+41:12:01.6 |
HIP 6341 |
18.59 |
| 2026-09-25 00:00 |
01:22:27.98 |
+41:11:58.2 |
HIP 6341 |
18.27 |
| 2026-09-25 12:00 |
01:22:25.62 |
+41:11:54.5 |
HIP 6341 |
17.96 |
| 2026-09-26 00:00 |
01:22:23.24 |
+41:11:50.7 |
HIP 6341 |
17.64 |
| 2026-09-26 12:00 |
01:22:20.86 |
+41:11:46.8 |
HIP 6341 |
17.33 |
| 2026-09-27 00:00 |
01:22:18.48 |
+41:11:42.7 |
HIP 6341 |
17.02 |
| 2026-09-27 12:00 |
01:22:16.08 |
+41:11:38.4 |
HIP 6341 |
16.72 |
| 2026-09-28 00:00 |
01:22:13.68 |
+41:11:34.0 |
HIP 6341 |
16.42 |
| 2026-09-28 12:00 |
01:22:11.28 |
+41:11:29.4 |
HIP 6341 |
16.12 |
| 2026-09-29 00:00 |
01:22:08.86 |
+41:11:24.7 |
HIP 6341 |
15.83 |
| 2026-09-29 12:00 |
01:22:06.44 |
+41:11:19.8 |
HIP 6341 |
15.55 |
| 2026-09-30 00:00 |
01:22:04.02 |
+41:11:14.7 |
HIP 6341 |
15.27 |
| 2026-09-30 12:00 |
01:22:01.59 |
+41:11:09.5 |
HIP 6341 |
15.00 |
| 2026-10-01 00:00 |
01:21:59.15 |
+41:11:04.1 |
HIP 6341 |
14.73 |
| 2026-10-01 12:00 |
01:21:56.70 |
+41:10:58.6 |
HIP 6341 |
14.47 |
| 2026-10-02 00:00 |
01:21:54.26 |
+41:10:52.9 |
HIP 6341 |
14.22 |
| 2026-10-02 12:00 |
01:21:51.80 |
+41:10:47.0 |
HIP 6341 |
13.98 |
| 2026-10-03 00:00 |
01:21:49.34 |
+41:10:41.0 |
HIP 6341 |
13.75 |
| 2026-10-03 12:00 |
01:21:46.88 |
+41:10:34.8 |
HIP 6341 |
13.53 |
| 2026-10-04 00:00 |
01:21:44.41 |
+41:10:28.5 |
HIP 6341 |
13.31 |
| 2026-10-04 12:00 |
01:21:41.94 |
+41:10:22.0 |
HIP 6341 |
13.11 |
| 2026-10-05 00:00 |
01:21:39.46 |
+41:10:15.4 |
HIP 6341 |
12.92 |
| 2026-10-05 12:00 |
01:21:36.98 |
+41:10:08.6 |
HIP 6341 |
12.75 |
| 2026-10-06 00:00 |
01:21:34.50 |
+41:10:01.7 |
HIP 6341 |
12.58 |
| 2026-10-06 12:00 |
01:21:32.01 |
+41:09:54.6 |
HIP 6341 |
12.43 |
| 2026-10-07 00:00 |
01:21:29.52 |
+41:09:47.3 |
HIP 6341 |
12.30 |
| 2026-10-07 12:00 |
01:21:27.02 |
+41:09:39.9 |
HIP 6341 |
12.18 |
| 2026-10-08 00:00 |
01:21:24.52 |
+41:09:32.3 |
HIP 6341 |
12.07 |
| 2026-10-08 12:00 |
01:21:22.02 |
+41:09:24.6 |
HIP 6341 |
11.99 |
| 2026-10-09 00:00 |
01:21:19.52 |
+41:09:16.7 |
HIP 6341 |
11.92 |
| 2026-10-09 12:00 |
01:21:17.01 |
+41:09:08.7 |
HIP 6341 |
11.86 |
| 2026-10-10 00:00 |
01:21:14.50 |
+41:09:00.5 |
HIP 6341 |
11.83 |
| 2026-10-10 12:00 |
01:21:11.99 |
+41:08:52.2 |
HIP 6341 |
11.81 |
| 2026-10-11 00:00 |
01:21:09.48 |
+41:08:43.7 |
HIP 6341 |
11.81 |