C/1981 G1 (Elias)

メタデータ

項目
Designation C/1981 G1 (Elias)
Type C
Perihelion (tp_cal, UTC) 1981-08-18T09:31:39.573120Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:29:29Z
Obs used 20
NEO -
M1 -
K1 -
PC 0.030
オスキュレーティング軌道要素
項目
Epoch (epoch_cal, TDB) 1982-01-23.0000000
e 1.00140214
q (au) 4.742646
a (au) -3382.426552
i (deg) 115.300346
Ω (om, deg) 176.713357
ω (w, deg) 310.265581
M (ma, deg) 0.000790

等級

C/1981 G1 (Elias) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (1.266 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目
H0 1.266
n 6.000
gf 1.000
gb -1.000
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)
2026-07-29 00:00 00:44:08.42 +79:43:53.9 HIP 4090 23.13
2026-07-29 12:00 00:44:04.60 +79:44:14.6 HIP 4090 23.19
2026-07-30 00:00 00:44:00.72 +79:44:35.2 HIP 4090 23.27
2026-07-30 12:00 00:43:56.75 +79:44:55.6 HIP 4090 23.35
2026-07-31 00:00 00:43:52.72 +79:45:16.0 HIP 4090 23.44
2026-07-31 12:00 00:43:48.61 +79:45:36.3 HIP 4090 23.54
2026-08-01 00:00 00:43:44.43 +79:45:56.4 HIP 4090 23.65
2026-08-01 12:00 00:43:40.18 +79:46:16.4 HIP 4090 23.76
2026-08-02 00:00 00:43:35.85 +79:46:36.4 HIP 4090 23.89
2026-08-02 12:00 00:43:31.45 +79:46:56.1 HIP 4090 24.03
2026-08-03 00:00 00:43:26.98 +79:47:15.8 HIP 4090 24.17
2026-08-03 12:00 00:43:22.43 +79:47:35.4 HIP 4090 24.32
2026-08-04 00:00 00:43:17.82 +79:47:54.8 HIP 4090 24.49
2026-08-04 12:00 00:43:13.13 +79:48:14.1 HIP 4090 24.65
2026-08-05 00:00 00:43:08.37 +79:48:33.2 HIP 4090 24.83
2026-08-05 12:00 00:43:03.54 +79:48:52.3 HIP 2971 24.69
2026-08-06 00:00 00:42:58.63 +79:49:11.2 HIP 2971 24.31
2026-08-06 12:00 00:42:53.66 +79:49:29.9 HIP 2971 23.93
2026-08-07 00:00 00:42:48.61 +79:49:48.6 HIP 2971 23.55
2026-08-07 12:00 00:42:43.50 +79:50:07.1 HIP 2971 23.17
2026-08-08 00:00 00:42:38.31 +79:50:25.4 HIP 2971 22.78
2026-08-08 12:00 00:42:33.05 +79:50:43.7 HIP 2971 22.40
2026-08-09 00:00 00:42:27.73 +79:51:01.7 HIP 2971 22.02
2026-08-09 12:00 00:42:22.33 +79:51:19.7 HIP 2971 21.64
2026-08-10 00:00 00:42:16.87 +79:51:37.5 HIP 2971 21.27
2026-08-10 12:00 00:42:11.33 +79:51:55.1 HIP 2971 20.89
2026-08-11 00:00 00:42:05.73 +79:52:12.6 HIP 2971 20.51
2026-08-11 12:00 00:42:00.06 +79:52:29.9 HIP 2971 20.13
2026-08-12 00:00 00:41:54.32 +79:52:47.1 HIP 2971 19.75
2026-08-12 12:00 00:41:48.51 +79:53:04.1 HIP 2971 19.38
2026-08-13 00:00 00:41:42.63 +79:53:21.0 HIP 2971 19.00
2026-08-13 12:00 00:41:36.69 +79:53:37.7 HIP 2971 18.63
2026-08-14 00:00 00:41:30.68 +79:53:54.3 HIP 2971 18.26
2026-08-14 12:00 00:41:24.61 +79:54:10.7 HIP 2971 17.89
2026-08-15 00:00 00:41:18.47 +79:54:26.9 HIP 2971 17.52
2026-08-15 12:00 00:41:12.26 +79:54:43.0 HIP 2971 17.15
2026-08-16 00:00 00:41:05.99 +79:54:58.9 HIP 2971 16.78
2026-08-16 12:00 00:40:59.66 +79:55:14.7 HIP 2971 16.42
2026-08-17 00:00 00:40:53.26 +79:55:30.2 HIP 2971 16.05
2026-08-17 12:00 00:40:46.80 +79:55:45.6 HIP 2971 15.69
2026-08-18 00:00 00:40:40.28 +79:56:00.9 HIP 2971 15.33
2026-08-18 12:00 00:40:33.69 +79:56:15.9 HIP 2971 14.98
2026-08-19 00:00 00:40:27.04 +79:56:30.8 HIP 2971 14.62