C/1975 E1 (Bradfield)

メタデータ

項目 値
Designation C/1975 E1 (Bradfield)
Type C
Perihelion (tp_cal, UTC) 1975-04-04T13:55:24.000960Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:29:24Z
Obs used 52
NEO -
M1 -
K1 -
PC 0.030
オスキュレーティング軌道要素
項目 値
Epoch (epoch_cal, TDB) 1975-06-11.0000000
e 1.00140639
q (au) 1.216946
a (au) -865.298894
i (deg) 55.243879
Ω (om, deg) 157.908852
ω (w, deg) 264.130708
M (ma, deg) 0.002611

等級

C/1975 E1 (Bradfield) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (10.105 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目 値
H0 10.105
n 6.000
gf 1.000
gb -0.804
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

天体暦

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-09-20 00:00 15:19:14.47 +33:55:16.0 HIP 74914 11.54
2026-09-20 12:00 15:19:15.54 +33:54:59.3 HIP 74914 11.89
2026-09-21 00:00 15:19:16.62 +33:54:42.7 HIP 74914 12.24
2026-09-21 12:00 15:19:17.72 +33:54:26.2 HIP 74914 12.60
2026-09-22 00:00 15:19:18.82 +33:54:09.7 HIP 74914 12.95
2026-09-22 12:00 15:19:19.94 +33:53:53.3 HIP 74914 13.31
2026-09-23 00:00 15:19:21.07 +33:53:37.0 HIP 74914 13.67
2026-09-23 12:00 15:19:22.21 +33:53:20.8 HIP 74914 14.03
2026-09-24 00:00 15:19:23.36 +33:53:04.6 HIP 74914 14.39
2026-09-24 12:00 15:19:24.53 +33:52:48.5 HIP 74914 14.75
2026-09-25 00:00 15:19:25.70 +33:52:32.5 HIP 74914 15.11
2026-09-25 12:00 15:19:26.89 +33:52:16.5 HIP 74914 15.47
2026-09-26 00:00 15:19:28.09 +33:52:00.6 HIP 74914 15.83
2026-09-26 12:00 15:19:29.30 +33:51:44.8 HIP 74914 16.20
2026-09-27 00:00 15:19:30.52 +33:51:29.1 HIP 74914 16.56
2026-09-27 12:00 15:19:31.75 +33:51:13.5 HIP 74914 16.93
2026-09-28 00:00 15:19:32.99 +33:50:57.9 HIP 74914 17.29
2026-09-28 12:00 15:19:34.25 +33:50:42.4 HIP 74914 17.66
2026-09-29 00:00 15:19:35.51 +33:50:27.0 HIP 74914 18.02
2026-09-29 12:00 15:19:36.79 +33:50:11.7 HIP 74914 18.39
2026-09-30 00:00 15:19:38.07 +33:49:56.4 HIP 74914 18.76
2026-09-30 12:00 15:19:39.37 +33:49:41.3 HIP 74914 19.13
2026-10-01 00:00 15:19:40.68 +33:49:26.2 HIP 74914 19.50
2026-10-01 12:00 15:19:41.99 +33:49:11.3 HIP 74914 19.87
2026-10-02 00:00 15:19:43.32 +33:48:56.4 HIP 74914 20.24
2026-10-02 12:00 15:19:44.66 +33:48:41.6 HIP 74914 20.61
2026-10-03 00:00 15:19:46.01 +33:48:26.9 HIP 74914 20.98
2026-10-03 12:00 15:19:47.37 +33:48:12.3 HIP 74914 21.36
2026-10-04 00:00 15:19:48.74 +33:47:57.7 HIP 74914 21.73
2026-10-04 12:00 15:19:50.12 +33:47:43.3 HIP 74914 22.10
2026-10-05 00:00 15:19:51.51 +33:47:29.0 HIP 74914 22.47
2026-10-05 12:00 15:19:52.90 +33:47:14.7 HIP 74914 22.85
2026-10-06 00:00 15:19:54.31 +33:47:00.6 HIP 74914 23.22
2026-10-06 12:00 15:19:55.73 +33:46:46.6 HIP 74914 23.60
2026-10-07 00:00 15:19:57.16 +33:46:32.6 HIP 74914 23.97
2026-10-07 12:00 15:19:58.59 +33:46:18.8 HIP 74914 24.35
2026-10-08 00:00 15:20:00.04 +33:46:05.1 HIP 74914 24.72
2026-10-08 12:00 15:20:01.50 +33:45:51.4 HIP 74914 25.10
2026-10-09 00:00 15:20:02.96 +33:45:37.9 HIP 74914 25.48
2026-10-09 12:00 15:20:04.43 +33:45:24.5 HIP 74914 25.85
2026-10-10 00:00 15:20:05.92 +33:45:11.2 HIP 74914 26.23
2026-10-10 12:00 15:20:07.41 +33:44:58.0 HIP 74914 26.60
2026-10-11 00:00 15:20:08.91 +33:44:44.9 HIP 74914 26.98