メタデータ
| 項目 |
値 |
| Designation |
C/2020 F8 (SWAN) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-05-27T13:06:40.423680Z |
| Orbit solution date (soln_date, UTC) |
2025-01-13T11:42:04Z |
| Obs used |
376 |
| NEO |
- |
| M1 |
11.600 |
| K1 |
4.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2020-04-24.0000000 |
| e |
0.99984071 |
| q (au) |
0.430317 |
| a (au) |
2701.498705 |
| i (deg) |
110.796078 |
| Ω (om, deg) |
260.028658 |
| ω (w, deg) |
68.198142 |
| M (ma, deg) |
359.999765 |
等級
散乱 + 全体線形
$$
M_a = (9.818 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
9.818 |
| n |
2.000 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.800 |
| δ90 |
1.000 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2019-10-22 |
2020-05-04 |
+12.2165 |
-0.587 |
| 2020-05-04 |
2020-05-26 |
-11.0290 |
-2.641 |
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 |
04:31:51.60 |
-24:09:36.0 |
HIP 21133 |
3.07 |
| 2026-07-29 12:00 |
04:31:55.12 |
-24:10:32.1 |
HIP 21133 |
4.21 |
| 2026-07-30 00:00 |
04:31:58.59 |
-24:11:28.5 |
HIP 21133 |
5.39 |
| 2026-07-30 12:00 |
04:32:02.01 |
-24:12:25.4 |
HIP 21133 |
6.58 |
| 2026-07-31 00:00 |
04:32:05.39 |
-24:13:22.6 |
HIP 21133 |
7.79 |
| 2026-07-31 12:00 |
04:32:08.73 |
-24:14:20.2 |
HIP 21133 |
9.01 |
| 2026-08-01 00:00 |
04:32:12.02 |
-24:15:18.2 |
HIP 21133 |
10.22 |
| 2026-08-01 12:00 |
04:32:15.26 |
-24:16:16.5 |
HIP 21133 |
11.44 |
| 2026-08-02 00:00 |
04:32:18.45 |
-24:17:15.3 |
HIP 21133 |
12.65 |
| 2026-08-02 12:00 |
04:32:21.60 |
-24:18:14.4 |
HIP 21133 |
13.87 |
| 2026-08-03 00:00 |
04:32:24.70 |
-24:19:13.9 |
HIP 21133 |
15.09 |
| 2026-08-03 12:00 |
04:32:27.75 |
-24:20:13.7 |
HIP 21133 |
16.30 |
| 2026-08-04 00:00 |
04:32:30.75 |
-24:21:13.9 |
HIP 21133 |
17.52 |
| 2026-08-04 12:00 |
04:32:33.71 |
-24:22:14.5 |
HIP 21133 |
18.73 |
| 2026-08-05 00:00 |
04:32:36.61 |
-24:23:15.4 |
HIP 21133 |
19.94 |
| 2026-08-05 12:00 |
04:32:39.47 |
-24:24:16.7 |
HIP 21133 |
21.15 |
| 2026-08-06 00:00 |
04:32:42.28 |
-24:25:18.3 |
HIP 21133 |
22.36 |
| 2026-08-06 12:00 |
04:32:45.04 |
-24:26:20.3 |
HIP 21133 |
23.57 |
| 2026-08-07 00:00 |
04:32:47.74 |
-24:27:22.6 |
HIP 21133 |
24.78 |
| 2026-08-07 12:00 |
04:32:50.40 |
-24:28:25.3 |
HIP 21133 |
25.98 |
| 2026-08-08 00:00 |
04:32:53.01 |
-24:29:28.3 |
HIP 21133 |
27.19 |
| 2026-08-08 12:00 |
04:32:55.57 |
-24:30:31.6 |
HIP 21133 |
28.39 |
| 2026-08-09 00:00 |
04:32:58.07 |
-24:31:35.3 |
HIP 21133 |
29.59 |
| 2026-08-09 12:00 |
04:33:00.53 |
-24:32:39.3 |
HIP 21133 |
30.79 |
| 2026-08-10 00:00 |
04:33:02.93 |
-24:33:43.6 |
HIP 21381 |
30.70 |
| 2026-08-10 12:00 |
04:33:05.28 |
-24:34:48.3 |
HIP 21381 |
30.24 |
| 2026-08-11 00:00 |
04:33:07.58 |
-24:35:53.2 |
HIP 21381 |
29.84 |
| 2026-08-11 12:00 |
04:33:09.83 |
-24:36:58.5 |
HIP 21381 |
29.50 |
| 2026-08-12 00:00 |
04:33:12.03 |
-24:38:04.1 |
HIP 21381 |
29.21 |
| 2026-08-12 12:00 |
04:33:14.17 |
-24:39:10.0 |
HIP 21381 |
28.99 |
| 2026-08-13 00:00 |
04:33:16.26 |
-24:40:16.2 |
HIP 21381 |
28.82 |
| 2026-08-13 12:00 |
04:33:18.29 |
-24:41:22.6 |
HIP 21381 |
28.72 |
| 2026-08-14 00:00 |
04:33:20.27 |
-24:42:29.4 |
HIP 21381 |
28.68 |
| 2026-08-14 12:00 |
04:33:22.20 |
-24:43:36.5 |
HIP 21354 |
28.11 |
| 2026-08-15 00:00 |
04:33:24.08 |
-24:44:43.8 |
HIP 21354 |
27.05 |
| 2026-08-15 12:00 |
04:33:25.90 |
-24:45:51.4 |
HIP 21354 |
26.00 |
| 2026-08-16 00:00 |
04:33:27.66 |
-24:46:59.3 |
HIP 21354 |
24.98 |
| 2026-08-16 12:00 |
04:33:29.37 |
-24:48:07.5 |
HIP 21354 |
23.99 |
| 2026-08-17 00:00 |
04:33:31.03 |
-24:49:15.9 |
HIP 21354 |
23.02 |
| 2026-08-17 12:00 |
04:33:32.63 |
-24:50:24.6 |
HIP 21354 |
22.08 |
| 2026-08-18 00:00 |
04:33:34.18 |
-24:51:33.5 |
HIP 21354 |
21.18 |
| 2026-08-18 12:00 |
04:33:35.67 |
-24:52:42.7 |
HIP 21354 |
20.32 |
| 2026-08-19 00:00 |
04:33:37.10 |
-24:53:52.1 |
HIP 21354 |
19.50 |