C/2020 F2 (ATLAS)

メタデータ

項目 値
Designation C/2020 F2 (ATLAS)
Type C
Perihelion (tp_cal, UTC) 2022-07-15T21:34:18.912000Z
Orbit solution date (soln_date, UTC) 2026-03-07T14:42:52Z
Obs used 1649
NEO -
M1 6.300
K1 7.250
PC 0.030
オスキュレーティング軌道要素
項目 値
Epoch (epoch_cal, TDB) 2022-04-08.0000000
e 1.00484187
q (au) 8.817057
a (au) -1821.002957
i (deg) 163.583705
Ω (om, deg) 250.268049
ω (w, deg) 48.361233
M (ma, deg) -0.001254

等級

C/2020 F2 (ATLAS) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (-1.509 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目 値
H0 -1.509
n 6.000
gf 0.831
gb -0.928
k 1.000
δ90 1.136
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

残差 (区間線形)

$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$

開始日 (UTC) 終了日 (UTC) a b
2019-05-27 2022-07-14 +9.9375 -9.585
2022-07-16 2026-02-20 +11.9466 -11.468

log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)

天体暦

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-09-20 00:00 09:48:58.11 +28:18:51.5 HIP 48093 15.02
2026-09-20 12:00 09:49:02.73 +28:18:46.5 HIP 48093 15.67
2026-09-21 00:00 09:49:07.30 +28:18:42.0 HIP 48093 16.35
2026-09-21 12:00 09:49:11.83 +28:18:37.9 HIP 48093 17.05
2026-09-22 00:00 09:49:16.32 +28:18:34.2 HIP 48093 17.76
2026-09-22 12:00 09:49:20.76 +28:18:31.0 HIP 48093 18.49
2026-09-23 00:00 09:49:25.16 +28:18:28.2 HIP 48093 19.23
2026-09-23 12:00 09:49:29.52 +28:18:25.9 HIP 48093 19.98
2026-09-24 00:00 09:49:33.83 +28:18:24.0 HIP 48093 20.73
2026-09-24 12:00 09:49:38.09 +28:18:22.6 HIP 48093 21.49
2026-09-25 00:00 09:49:42.31 +28:18:21.7 HIP 48093 22.24
2026-09-25 12:00 09:49:46.48 +28:18:21.2 HIP 48093 23.00
2026-09-26 00:00 09:49:50.60 +28:18:21.1 HIP 48093 23.75
2026-09-26 12:00 09:49:54.68 +28:18:21.6 HIP 48093 24.50
2026-09-27 00:00 09:49:58.71 +28:18:22.5 HIP 48093 25.25
2026-09-27 12:00 09:50:02.69 +28:18:23.8 HIP 48093 26.00
2026-09-28 00:00 09:50:06.62 +28:18:25.6 HIP 48093 26.73
2026-09-28 12:00 09:50:10.50 +28:18:27.9 HIP 48093 27.47
2026-09-29 00:00 09:50:14.33 +28:18:30.7 HIP 48093 28.19
2026-09-29 12:00 09:50:18.11 +28:18:33.9 HIP 48093 28.91
2026-09-30 00:00 09:50:21.84 +28:18:37.6 HIP 48093 29.62
2026-09-30 12:00 09:50:25.51 +28:18:41.8 HIP 48093 30.32
2026-10-01 00:00 09:50:29.14 +28:18:46.4 HIP 48093 31.02
2026-10-01 12:00 09:50:32.71 +28:18:51.6 HIP 48093 31.70
2026-10-02 00:00 09:50:36.23 +28:18:57.2 HIP 48093 32.38
2026-10-02 12:00 09:50:39.69 +28:19:03.3 HIP 48093 33.05
2026-10-03 00:00 09:50:43.10 +28:19:09.8 HIP 48093 33.70
2026-10-03 12:00 09:50:46.45 +28:19:16.9 HIP 48093 34.35
2026-10-04 00:00 09:50:49.75 +28:19:24.4 HIP 48093 34.99
2026-10-04 12:00 09:50:52.99 +28:19:32.5 HIP 48093 35.61
2026-10-05 00:00 09:50:56.17 +28:19:41.0 HIP 48093 36.23
2026-10-05 12:00 09:50:59.30 +28:19:50.0 HIP 48093 36.83
2026-10-06 00:00 09:51:02.37 +28:19:59.5 HIP 48342 37.17
2026-10-06 12:00 09:51:05.38 +28:20:09.6 HIP 48342 36.96
2026-10-07 00:00 09:51:08.33 +28:20:20.1 HIP 48342 36.76
2026-10-07 12:00 09:51:11.22 +28:20:31.1 HIP 48342 36.56
2026-10-08 00:00 09:51:14.05 +28:20:42.6 HIP 48342 36.36
2026-10-08 12:00 09:51:16.81 +28:20:54.6 HIP 48342 36.16
2026-10-09 00:00 09:51:19.52 +28:21:07.1 HIP 48342 35.96
2026-10-09 12:00 09:51:22.16 +28:21:20.2 HIP 48342 35.77
2026-10-10 00:00 09:51:24.74 +28:21:33.7 HIP 48342 35.57
2026-10-10 12:00 09:51:27.26 +28:21:47.8 HIP 48342 35.38
2026-10-11 00:00 09:51:29.71 +28:22:02.3 HIP 48549 34.91