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) |
| 2026-03-26 00:00 |
01:19:43.99 |
+40:03:05.0 |
HIP 6144 |
11.08 |
| 2026-03-26 12:00 |
01:19:46.22 |
+40:03:09.3 |
HIP 6144 |
11.49 |
| 2026-03-27 00:00 |
01:19:48.46 |
+40:03:13.7 |
HIP 6144 |
11.90 |
| 2026-03-27 12:00 |
01:19:50.71 |
+40:03:18.3 |
HIP 6144 |
12.32 |
| 2026-03-28 00:00 |
01:19:52.96 |
+40:03:23.0 |
HIP 6144 |
12.74 |
| 2026-03-28 12:00 |
01:19:55.22 |
+40:03:27.9 |
HIP 6144 |
13.16 |
| 2026-03-29 00:00 |
01:19:57.48 |
+40:03:32.9 |
HIP 6144 |
13.59 |
| 2026-03-29 12:00 |
01:19:59.74 |
+40:03:38.1 |
HIP 6144 |
14.02 |
| 2026-03-30 00:00 |
01:20:02.01 |
+40:03:43.4 |
HIP 6144 |
14.45 |
| 2026-03-30 12:00 |
01:20:04.28 |
+40:03:48.8 |
HIP 6144 |
14.89 |
| 2026-03-31 00:00 |
01:20:06.56 |
+40:03:54.4 |
HIP 6144 |
15.32 |
| 2026-03-31 12:00 |
01:20:08.84 |
+40:04:00.2 |
HIP 6144 |
15.76 |
| 2026-04-01 00:00 |
01:20:11.13 |
+40:04:06.0 |
HIP 6144 |
16.20 |
| 2026-04-01 12:00 |
01:20:13.41 |
+40:04:12.1 |
HIP 6144 |
16.65 |
| 2026-04-02 00:00 |
01:20:15.71 |
+40:04:18.2 |
HIP 6144 |
17.09 |
| 2026-04-02 12:00 |
01:20:18.00 |
+40:04:24.5 |
HIP 6144 |
17.54 |
| 2026-04-03 00:00 |
01:20:20.30 |
+40:04:30.9 |
HIP 6144 |
17.99 |
| 2026-04-03 12:00 |
01:20:22.60 |
+40:04:37.5 |
HIP 6144 |
18.43 |
| 2026-04-04 00:00 |
01:20:24.90 |
+40:04:44.2 |
HIP 6144 |
18.89 |
| 2026-04-04 12:00 |
01:20:27.21 |
+40:04:51.1 |
HIP 6144 |
19.34 |
| 2026-04-05 00:00 |
01:20:29.52 |
+40:04:58.1 |
HIP 6144 |
19.79 |
| 2026-04-05 12:00 |
01:20:31.83 |
+40:05:05.2 |
HIP 6144 |
20.25 |
| 2026-04-06 00:00 |
01:20:34.15 |
+40:05:12.5 |
HIP 6144 |
20.70 |
| 2026-04-06 12:00 |
01:20:36.46 |
+40:05:19.9 |
HIP 6144 |
21.16 |
| 2026-04-07 00:00 |
01:20:38.78 |
+40:05:27.4 |
HIP 6144 |
21.62 |
| 2026-04-07 12:00 |
01:20:41.10 |
+40:05:35.1 |
HIP 6144 |
22.08 |
| 2026-04-08 00:00 |
01:20:43.42 |
+40:05:42.9 |
HIP 6144 |
22.54 |
| 2026-04-08 12:00 |
01:20:45.74 |
+40:05:50.8 |
HIP 6144 |
23.01 |
| 2026-04-09 00:00 |
01:20:48.07 |
+40:05:58.9 |
HIP 6144 |
23.47 |
| 2026-04-09 12:00 |
01:20:50.39 |
+40:06:07.1 |
HIP 6144 |
23.93 |
| 2026-04-10 00:00 |
01:20:52.72 |
+40:06:15.4 |
HIP 6144 |
24.40 |
| 2026-04-10 12:00 |
01:20:55.04 |
+40:06:23.9 |
HIP 6144 |
24.86 |
| 2026-04-11 00:00 |
01:20:57.37 |
+40:06:32.5 |
HIP 6144 |
25.33 |
| 2026-04-11 12:00 |
01:20:59.70 |
+40:06:41.2 |
HIP 6144 |
25.80 |
| 2026-04-12 00:00 |
01:21:02.02 |
+40:06:50.1 |
HIP 6144 |
26.27 |
| 2026-04-12 12:00 |
01:21:04.35 |
+40:06:59.1 |
HIP 6144 |
26.74 |
| 2026-04-13 00:00 |
01:21:06.68 |
+40:07:08.2 |
HIP 6144 |
27.21 |
| 2026-04-13 12:00 |
01:21:09.01 |
+40:07:17.4 |
HIP 6144 |
27.68 |
| 2026-04-14 00:00 |
01:21:11.34 |
+40:07:26.8 |
HIP 6144 |
28.15 |
| 2026-04-14 12:00 |
01:21:13.66 |
+40:07:36.3 |
HIP 6144 |
28.62 |
| 2026-04-15 00:00 |
01:21:15.99 |
+40:07:45.9 |
HIP 6144 |
29.10 |
| 2026-04-15 12:00 |
01:21:18.31 |
+40:07:55.7 |
HIP 6144 |
29.57 |
| 2026-04-16 00:00 |
01:21:20.64 |
+40:08:05.5 |
HIP 6144 |
30.04 |