C/2021 G3 (PANSTARRS)

メタデータ

項目 値
Designation C/2021 G3 (PANSTARRS)
Type C
Perihelion (tp_cal, UTC) 2021-10-18T17:46:41.067840Z
Orbit solution date (soln_date, UTC) 2022-12-08T23:43:00Z
Obs used 63
NEO -
M1 7.600
K1 14.750
PC -
オスキュレーティング軌道要素
項目 値
Epoch (epoch_cal, TDB) 2021-07-12.0000000
e 1.00119266
q (au) 5.181101
a (au) -4344.158799
i (deg) 102.884132
Ω (om, deg) 147.418441
ω (w, deg) 10.663883
M (ma, deg) -0.000340

等級

C/2021 G3 (PANSTARRS) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (14.019 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目 値
H0 14.019
n 2.000
gf 0.997
gb -1.000
k 1.000
δ90 9.990
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 20:51:07.31 +57:17:25.4 HIP 102943 13.89
2026-09-20 12:00 20:50:57.60 +57:15:04.0 HIP 102943 11.90
2026-09-21 00:00 20:50:48.03 +57:12:41.8 HIP 102943 10.23
2026-09-21 12:00 20:50:38.58 +57:10:18.9 HIP 102943 9.04
2026-09-22 00:00 20:50:29.26 +57:07:55.4 HIP 102943 8.55
2026-09-22 12:00 20:50:20.07 +57:05:31.1 HIP 102943 8.89
2026-09-23 00:00 20:50:11.01 +57:03:06.2 HIP 102943 9.96
2026-09-23 12:00 20:50:02.08 +57:00:40.7 HIP 102943 11.57
2026-09-24 00:00 20:49:53.29 +56:58:14.5 HIP 102858 10.88
2026-09-24 12:00 20:49:44.62 +56:55:47.6 HIP 102858 9.13
2026-09-25 00:00 20:49:36.09 +56:53:20.2 HIP 102858 7.92
2026-09-25 12:00 20:49:27.69 +56:50:52.1 HIP 102858 7.52
2026-09-26 00:00 20:49:19.42 +56:48:23.4 HIP 102858 8.07
2026-09-26 12:00 20:49:11.29 +56:45:54.2 HIP 102858 9.39
2026-09-27 00:00 20:49:03.29 +56:43:24.3 HIP 102858 11.21
2026-09-27 12:00 20:48:55.42 +56:40:53.9 HIP 102858 13.34
2026-09-28 00:00 20:48:47.69 +56:38:23.0 HIP 102858 15.65
2026-09-28 12:00 20:48:40.09 +56:35:51.4 HIP 102858 18.07
2026-09-29 00:00 20:48:32.63 +56:33:19.4 HIP 102858 20.57
2026-09-29 12:00 20:48:25.30 +56:30:46.8 HIP 102858 23.11
2026-09-30 00:00 20:48:18.11 +56:28:13.7 HIP 102858 25.69
2026-09-30 12:00 20:48:11.05 +56:25:40.1 HIP 102638 24.28
2026-10-01 00:00 20:48:04.13 +56:23:06.0 HIP 102638 21.63
2026-10-01 12:00 20:47:57.34 +56:20:31.4 HIP 102638 18.99
2026-10-02 00:00 20:47:50.70 +56:17:56.3 HIP 102638 16.38
2026-10-02 12:00 20:47:44.18 +56:15:20.8 HIP 102638 13.82
2026-10-03 00:00 20:47:37.81 +56:12:44.8 HIP 102638 11.33
2026-10-03 12:00 20:47:31.57 +56:10:08.4 HIP 102638 8.97
2026-10-04 00:00 20:47:25.47 +56:07:31.6 HIP 102638 6.91
2026-10-04 12:00 20:47:19.50 +56:04:54.3 HIP 102638 5.46
2026-10-05 00:00 20:47:13.68 +56:02:16.6 HIP 102638 5.18
2026-10-05 12:00 20:47:07.99 +55:59:38.6 HIP 102638 6.23
2026-10-06 00:00 20:47:02.44 +55:57:00.1 HIP 102597 5.66
2026-10-06 12:00 20:46:57.03 +55:54:21.3 HIP 102597 5.02
2026-10-07 00:00 20:46:51.76 +55:51:42.1 HIP 102597 5.77
2026-10-07 12:00 20:46:46.62 +55:49:02.5 HIP 102597 7.51
2026-10-08 00:00 20:46:41.63 +55:46:22.7 HIP 102597 9.72
2026-10-08 12:00 20:46:36.77 +55:43:42.5 HIP 102597 12.15
2026-10-09 00:00 20:46:32.05 +55:41:02.0 HIP 102598 10.94
2026-10-09 12:00 20:46:27.47 +55:38:21.1 HIP 102598 10.09
2026-10-10 00:00 20:46:23.03 +55:35:40.0 HIP 102598 9.93
2026-10-10 12:00 20:46:18.73 +55:32:58.7 HIP 102598 10.50
2026-10-11 00:00 20:46:14.57 +55:30:17.0 HIP 102598 11.69