Comet Archive

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C/2021 K3 (Catalina)

メタデータ

項目
Designation C/2021 K3 (Catalina)
Type C
Perihelion (tp_cal, UTC) 2022-02-02T08:11:00.119040Z
Orbit solution date (soln_date, UTC) 2022-06-07T21:45:11Z
Obs used 99
NEO -
M1 14.500
K1 4.500
PC -
オスキュレーティング軌道要素
項目
Epoch (epoch_cal, TDB) 2021-07-16.0000000
e 1.00356145
q (au) 5.230100
a (au) -1468.531415
i (deg) 134.804408
Ω (om, deg) 114.441510
ω (w, deg) 181.948465
M (ma, deg) -0.003526

等級

C/2021 K3 (Catalina) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (17.424 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目
H0 17.424
n 2.000
gf 1.000
gb -0.757
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)
2026-02-03 00:00 11:43:28.12 -50:17:05.7 HIP 57010 21.30
2026-02-03 12:00 11:43:12.30 -50:17:31.6 HIP 57010 18.96
2026-02-04 00:00 11:42:56.37 -50:17:56.2 HIP 57010 16.66
2026-02-04 12:00 11:42:40.34 -50:18:19.7 HIP 57010 14.45
2026-02-05 00:00 11:42:24.21 -50:18:41.9 HIP 57010 12.35
2026-02-05 12:00 11:42:07.97 -50:19:03.0 HIP 57010 10.46
2026-02-06 00:00 11:41:51.64 -50:19:22.8 HIP 57010 8.92
2026-02-06 12:00 11:41:35.21 -50:19:41.4 HIP 57010 7.95
2026-02-07 00:00 11:41:18.69 -50:19:58.7 HIP 57010 7.78
2026-02-07 12:00 11:41:02.07 -50:20:14.8 HIP 57010 8.46
2026-02-08 00:00 11:40:45.36 -50:20:29.7 HIP 57010 9.84
2026-02-08 12:00 11:40:28.55 -50:20:43.3 HIP 56904 10.10
2026-02-09 00:00 11:40:11.65 -50:20:55.6 HIP 56904 8.72
2026-02-09 12:00 11:39:54.66 -50:21:06.6 HIP 56904 8.05
2026-02-10 00:00 11:39:37.59 -50:21:16.4 HIP 56904 8.29
2026-02-10 12:00 11:39:20.43 -50:21:24.9 HIP 56904 9.38
2026-02-11 00:00 11:39:03.18 -50:21:32.1 HIP 56904 11.08
2026-02-11 12:00 11:38:45.84 -50:21:37.9 HIP 56776 10.22
2026-02-12 00:00 11:38:28.43 -50:21:42.5 HIP 56776 9.74
2026-02-12 12:00 11:38:10.93 -50:21:45.8 HIP 56776 10.01
2026-02-13 00:00 11:37:53.36 -50:21:47.7 HIP 56776 11.00
2026-02-13 12:00 11:37:35.70 -50:21:48.3 HIP 56714 12.39
2026-02-14 00:00 11:37:17.97 -50:21:47.6 HIP 56714 12.90
2026-02-14 12:00 11:37:00.17 -50:21:45.5 HIP 56714 14.00
2026-02-15 00:00 11:36:42.29 -50:21:42.1 HIP 56714 15.57
2026-02-15 12:00 11:36:24.34 -50:21:37.4 HIP 56714 17.49
2026-02-16 00:00 11:36:06.32 -50:21:31.2 HIP 56714 19.66
2026-02-16 12:00 11:35:48.23 -50:21:23.8 HIP 56714 22.01
2026-02-17 00:00 11:35:30.08 -50:21:15.0 HIP 56543 22.19
2026-02-17 12:00 11:35:11.86 -50:21:04.8 HIP 56430 20.84
2026-02-18 00:00 11:34:53.57 -50:20:53.2 HIP 56430 19.47
2026-02-18 12:00 11:34:35.23 -50:20:40.3 HIP 56430 18.45
2026-02-19 00:00 11:34:16.82 -50:20:25.9 HIP 56430 17.83
2026-02-19 12:00 11:33:58.36 -50:20:10.2 HIP 56430 17.67
2026-02-20 00:00 11:33:39.85 -50:19:53.1 HIP 56430 17.98
2026-02-20 12:00 11:33:21.27 -50:19:34.7 HIP 56430 18.76
2026-02-21 00:00 11:33:02.65 -50:19:14.8 HIP 56430 19.93
2026-02-21 12:00 11:32:43.98 -50:18:53.6 HIP 56430 21.46
2026-02-22 00:00 11:32:25.25 -50:18:30.9 HIP 56151 21.15
2026-02-22 12:00 11:32:06.48 -50:18:06.9 HIP 56151 18.97
2026-02-23 00:00 11:31:47.67 -50:17:41.5 HIP 56151 17.05
2026-02-23 12:00 11:31:28.81 -50:17:14.6 HIP 56151 15.51
2026-02-24 00:00 11:31:09.91 -50:16:46.4 HIP 56151 14.48