Comet Archive

Clear skies!

C/1978 A1 (West)

メタデータ

項目
Designation C/1978 A1 (West)
Type C
Perihelion (tp_cal, UTC) 1977-07-21T10:46:21.555840Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:29:26Z
Obs used 60
NEO -
M1 6.000
K1 8.500
PC -
オスキュレーティング軌道要素
項目
Epoch (epoch_cal, TDB) 1978-03-26.0000000
e 1.00269511
q (au) 5.606239
a (au) -2080.153011
i (deg) 116.921045
Ω (om, deg) 211.624226
ω (w, deg) 343.273891
M (ma, deg) 0.002572

等級

C/1978 A1 (West) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (-0.758 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目
H0 -0.758
n 6.000
gf 1.000
gb -0.506
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)
2026-02-03 00:00 02:34:04.59 +60:55:37.8 HIP 12067 15.39
2026-02-03 12:00 02:34:04.72 +60:55:18.4 HIP 12067 15.61
2026-02-04 00:00 02:34:04.88 +60:54:59.0 HIP 12067 15.82
2026-02-04 12:00 02:34:05.06 +60:54:39.6 HIP 12067 16.04
2026-02-05 00:00 02:34:05.27 +60:54:20.4 HIP 12067 16.26
2026-02-05 12:00 02:34:05.52 +60:54:01.2 HIP 12067 16.48
2026-02-06 00:00 02:34:05.79 +60:53:42.1 HIP 12067 16.70
2026-02-06 12:00 02:34:06.09 +60:53:23.0 HIP 12067 16.92
2026-02-07 00:00 02:34:06.42 +60:53:04.0 HIP 12067 17.14
2026-02-07 12:00 02:34:06.78 +60:52:45.1 HIP 12067 17.36
2026-02-08 00:00 02:34:07.17 +60:52:26.2 HIP 12067 17.58
2026-02-08 12:00 02:34:07.58 +60:52:07.5 HIP 12067 17.80
2026-02-09 00:00 02:34:08.03 +60:51:48.8 HIP 12067 18.02
2026-02-09 12:00 02:34:08.50 +60:51:30.1 HIP 12067 18.24
2026-02-10 00:00 02:34:09.00 +60:51:11.6 HIP 12067 18.46
2026-02-10 12:00 02:34:09.54 +60:50:53.1 HIP 12009 18.38
2026-02-11 00:00 02:34:10.10 +60:50:34.7 HIP 12009 18.06
2026-02-11 12:00 02:34:10.68 +60:50:16.4 HIP 12009 17.75
2026-02-12 00:00 02:34:11.30 +60:49:58.2 HIP 12009 17.44
2026-02-12 12:00 02:34:11.95 +60:49:40.1 HIP 12009 17.12
2026-02-13 00:00 02:34:12.62 +60:49:22.0 HIP 12009 16.81
2026-02-13 12:00 02:34:13.32 +60:49:04.1 HIP 12009 16.50
2026-02-14 00:00 02:34:14.05 +60:48:46.2 HIP 12009 16.19
2026-02-14 12:00 02:34:14.81 +60:48:28.4 HIP 12009 15.88
2026-02-15 00:00 02:34:15.59 +60:48:10.7 HIP 12009 15.57
2026-02-15 12:00 02:34:16.41 +60:47:53.1 HIP 12009 15.26
2026-02-16 00:00 02:34:17.25 +60:47:35.6 HIP 12009 14.95
2026-02-16 12:00 02:34:18.12 +60:47:18.2 HIP 12009 14.65
2026-02-17 00:00 02:34:19.01 +60:47:00.9 HIP 12009 14.34
2026-02-17 12:00 02:34:19.94 +60:46:43.7 HIP 12009 14.03
2026-02-18 00:00 02:34:20.89 +60:46:26.6 HIP 12009 13.73
2026-02-18 12:00 02:34:21.87 +60:46:09.5 HIP 12009 13.42
2026-02-19 00:00 02:34:22.87 +60:45:52.6 HIP 12009 13.12
2026-02-19 12:00 02:34:23.90 +60:45:35.8 HIP 12009 12.82
2026-02-20 00:00 02:34:24.96 +60:45:19.1 HIP 12009 12.52
2026-02-20 12:00 02:34:26.05 +60:45:02.5 HIP 12009 12.22
2026-02-21 00:00 02:34:27.16 +60:44:46.0 HIP 12009 11.92
2026-02-21 12:00 02:34:28.30 +60:44:29.6 HIP 12009 11.62
2026-02-22 00:00 02:34:29.47 +60:44:13.3 HIP 12009 11.33
2026-02-22 12:00 02:34:30.66 +60:43:57.1 HIP 12009 11.04
2026-02-23 00:00 02:34:31.88 +60:43:41.0 HIP 12009 10.74
2026-02-23 12:00 02:34:33.13 +60:43:25.1 HIP 12009 10.45
2026-02-24 00:00 02:34:34.40 +60:43:09.2 HIP 12009 10.17