Comet Archive

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C/2018 E2 (Barros)

メタデータ

項目
Designation C/2018 E2 (Barros)
Type C
Perihelion (tp_cal, UTC) 2017-12-23T16:27:32.230080Z
Orbit solution date (soln_date, UTC) 2022-07-06T03:12:21Z
Obs used 62
NEO -
M1 9.900
K1 10.250
PC 0.030
Discovery observation (MPC, UTC) 2018-03-12T22:14:13.056000Z
Discovery magnitude (MPC) 19.40 T
Discovery observatory (MPC) Y00 · SONEAR Observatory, Oliveira
オスキュレーティング軌道要素
項目
Epoch (epoch_cal, TDB) 2018-03-25.0000000
e 0.99760072
q (au) 3.922284
a (au) 1634.776323
i (deg) 97.742513
Ω (om, deg) 67.202099
ω (w, deg) 277.481389
M (ma, deg) 0.001362

等級

C/2018 E2 (Barros) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (6.323 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目
H0 6.323
n 6.000
gf 1.000
gb -0.968
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 02:14:03.77 +61:11:46.9 HIP 10224 18.80
2026-02-03 12:00 02:14:04.38 +61:10:51.9 HIP 10224 18.93
2026-02-04 00:00 02:14:05.09 +61:09:57.2 HIP 10224 19.12
2026-02-04 12:00 02:14:05.91 +61:09:02.8 HIP 10224 19.35
2026-02-05 00:00 02:14:06.83 +61:08:08.7 HIP 10224 19.64
2026-02-05 12:00 02:14:07.85 +61:07:15.0 HIP 10224 19.97
2026-02-06 00:00 02:14:08.97 +61:06:21.6 HIP 10224 20.35
2026-02-06 12:00 02:14:10.19 +61:05:28.5 HIP 10224 20.77
2026-02-07 00:00 02:14:11.52 +61:04:35.8 HIP 10224 21.23
2026-02-07 12:00 02:14:12.94 +61:03:43.4 HIP 10224 21.73
2026-02-08 00:00 02:14:14.46 +61:02:51.3 HIP 10224 22.26
2026-02-08 12:00 02:14:16.09 +61:01:59.6 HIP 10224 22.82
2026-02-09 00:00 02:14:17.81 +61:01:08.3 HIP 10585 23.15
2026-02-09 12:00 02:14:19.63 +61:00:17.3 HIP 10585 22.35
2026-02-10 00:00 02:14:21.55 +60:59:26.7 HIP 10585 21.56
2026-02-10 12:00 02:14:23.56 +60:58:36.5 HIP 10585 20.77
2026-02-11 00:00 02:14:25.67 +60:57:46.6 HIP 10585 19.99
2026-02-11 12:00 02:14:27.88 +60:56:57.1 HIP 10585 19.21
2026-02-12 00:00 02:14:30.19 +60:56:08.0 HIP 10585 18.43
2026-02-12 12:00 02:14:32.59 +60:55:19.3 HIP 10585 17.66
2026-02-13 00:00 02:14:35.09 +60:54:31.0 HIP 10585 16.89
2026-02-13 12:00 02:14:37.68 +60:53:43.0 HIP 10585 16.12
2026-02-14 00:00 02:14:40.37 +60:52:55.5 HIP 10585 15.36
2026-02-14 12:00 02:14:43.15 +60:52:08.3 HIP 10585 14.61
2026-02-15 00:00 02:14:46.02 +60:51:21.6 HIP 10585 13.86
2026-02-15 12:00 02:14:48.98 +60:50:35.3 HIP 10585 13.12
2026-02-16 00:00 02:14:52.04 +60:49:49.3 HIP 10585 12.39
2026-02-16 12:00 02:14:55.19 +60:49:03.8 HIP 10585 11.67
2026-02-17 00:00 02:14:58.43 +60:48:18.7 HIP 10585 10.95
2026-02-17 12:00 02:15:01.76 +60:47:34.1 HIP 10585 10.26
2026-02-18 00:00 02:15:05.18 +60:46:49.8 HIP 10585 9.58
2026-02-18 12:00 02:15:08.69 +60:46:06.0 HIP 10585 8.92
2026-02-19 00:00 02:15:12.29 +60:45:22.6 HIP 10585 8.28
2026-02-19 12:00 02:15:15.98 +60:44:39.7 HIP 10585 7.68
2026-02-20 00:00 02:15:19.76 +60:43:57.2 HIP 10585 7.11
2026-02-20 12:00 02:15:23.62 +60:43:15.1 HIP 10585 6.60
2026-02-21 00:00 02:15:27.57 +60:42:33.5 HIP 10585 6.15
2026-02-21 12:00 02:15:31.60 +60:41:52.3 HIP 10585 5.77
2026-02-22 00:00 02:15:35.72 +60:41:11.6 HIP 10575 5.11
2026-02-22 12:00 02:15:39.93 +60:40:31.3 HIP 10575 4.29
2026-02-23 00:00 02:15:44.22 +60:39:51.5 HIP 10575 3.47
2026-02-23 12:00 02:15:48.59 +60:39:12.1 HIP 10575 2.66
2026-02-24 00:00 02:15:53.04 +60:38:33.2 HIP 10575 1.87