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
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) |
| 2026-07-29 00:00 |
09:38:48.06 |
+29:01:49.0 |
HIP 47217 |
23.04 |
| 2026-07-29 12:00 |
09:38:53.87 |
+29:01:10.3 |
HIP 47217 |
24.45 |
| 2026-07-30 00:00 |
09:38:59.70 |
+29:00:31.8 |
HIP 47217 |
25.86 |
| 2026-07-30 12:00 |
09:39:05.54 |
+28:59:53.5 |
HIP 47217 |
27.27 |
| 2026-07-31 00:00 |
09:39:11.41 |
+28:59:15.4 |
HIP 47217 |
28.69 |
| 2026-07-31 12:00 |
09:39:17.29 |
+28:58:37.5 |
HIP 47217 |
30.11 |
| 2026-08-01 00:00 |
09:39:23.19 |
+28:57:59.7 |
HIP 47553 |
31.26 |
| 2026-08-01 12:00 |
09:39:29.10 |
+28:57:22.2 |
HIP 47553 |
29.88 |
| 2026-08-02 00:00 |
09:39:35.03 |
+28:56:44.9 |
HIP 47553 |
28.50 |
| 2026-08-02 12:00 |
09:39:40.98 |
+28:56:07.7 |
HIP 47553 |
27.12 |
| 2026-08-03 00:00 |
09:39:46.94 |
+28:55:30.8 |
HIP 47553 |
25.75 |
| 2026-08-03 12:00 |
09:39:52.91 |
+28:54:54.1 |
HIP 47553 |
24.38 |
| 2026-08-04 00:00 |
09:39:58.90 |
+28:54:17.6 |
HIP 47553 |
23.01 |
| 2026-08-04 12:00 |
09:40:04.89 |
+28:53:41.3 |
HIP 47553 |
21.66 |
| 2026-08-05 00:00 |
09:40:10.90 |
+28:53:05.2 |
HIP 47553 |
20.31 |
| 2026-08-05 12:00 |
09:40:16.93 |
+28:52:29.3 |
HIP 47553 |
18.98 |
| 2026-08-06 00:00 |
09:40:22.96 |
+28:51:53.7 |
HIP 47553 |
17.66 |
| 2026-08-06 12:00 |
09:40:29.01 |
+28:51:18.2 |
HIP 47553 |
16.36 |
| 2026-08-07 00:00 |
09:40:35.06 |
+28:50:43.0 |
HIP 47553 |
15.09 |
| 2026-08-07 12:00 |
09:40:41.12 |
+28:50:08.0 |
HIP 47553 |
13.84 |
| 2026-08-08 00:00 |
09:40:47.20 |
+28:49:33.3 |
HIP 47553 |
12.64 |
| 2026-08-08 12:00 |
09:40:53.28 |
+28:48:58.8 |
HIP 47553 |
11.49 |
| 2026-08-09 00:00 |
09:40:59.36 |
+28:48:24.5 |
HIP 47553 |
10.42 |
| 2026-08-09 12:00 |
09:41:05.46 |
+28:47:50.4 |
HIP 47553 |
9.44 |
| 2026-08-10 00:00 |
09:41:11.56 |
+28:47:16.6 |
HIP 47553 |
8.60 |
| 2026-08-10 12:00 |
09:41:17.67 |
+28:46:43.1 |
HIP 47553 |
7.92 |
| 2026-08-11 00:00 |
09:41:23.78 |
+28:46:09.8 |
HIP 47553 |
7.47 |
| 2026-08-11 12:00 |
09:41:29.90 |
+28:45:36.7 |
HIP 47553 |
7.28 |
| 2026-08-12 00:00 |
09:41:36.02 |
+28:45:03.9 |
HIP 47553 |
7.36 |
| 2026-08-12 12:00 |
09:41:42.15 |
+28:44:31.3 |
HIP 47582 |
6.21 |
| 2026-08-13 00:00 |
09:41:48.27 |
+28:43:59.1 |
HIP 47582 |
4.78 |
| 2026-08-13 12:00 |
09:41:54.40 |
+28:43:27.0 |
HIP 47582 |
3.36 |
| 2026-08-14 00:00 |
09:42:00.54 |
+28:42:55.3 |
HIP 47582 |
1.99 |
| 2026-08-14 12:00 |
09:42:06.67 |
+28:42:23.8 |
HIP 47582 |
0.89 |
| 2026-08-15 00:00 |
09:42:12.80 |
+28:41:52.5 |
HIP 47582 |
1.34 |
| 2026-08-15 12:00 |
09:42:18.93 |
+28:41:21.6 |
HIP 47582 |
2.64 |
| 2026-08-16 00:00 |
09:42:25.06 |
+28:40:50.9 |
HIP 47582 |
4.04 |
| 2026-08-16 12:00 |
09:42:31.19 |
+28:40:20.5 |
HIP 47582 |
5.45 |
| 2026-08-17 00:00 |
09:42:37.32 |
+28:39:50.4 |
HIP 47582 |
6.88 |
| 2026-08-17 12:00 |
09:42:43.44 |
+28:39:20.6 |
HIP 47582 |
8.30 |
| 2026-08-18 00:00 |
09:42:49.56 |
+28:38:51.0 |
HIP 47582 |
9.73 |
| 2026-08-18 12:00 |
09:42:55.68 |
+28:38:21.8 |
HIP 47582 |
11.15 |
| 2026-08-19 00:00 |
09:43:01.79 |
+28:37:52.8 |
HIP 47582 |
12.57 |