メタデータ
| 項目 |
値 |
| Designation |
C/2025 F2 (SWAN) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2025-05-01T03:51:29.594880Z |
| Orbit solution date (soln_date, UTC) |
2025-09-30T14:13:43Z |
| Obs used |
375 |
| NEO |
- |
| M1 |
12.300 |
| K1 |
13.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2025-03-22T12:00:00Z |
| Discovery magnitude (MPC) |
- |
| Discovery observatory (MPC) |
249 · SOHO |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2025-03-31.0000000 |
| e |
1.00013474 |
| q (au) |
0.333496 |
| a (au) |
-2475.174637 |
| i (deg) |
90.364801 |
| Ω (om, deg) |
329.839874 |
| ω (w, deg) |
153.835634 |
| M (ma, deg) |
-0.000249 |
等級
散乱 + 全体線形
$$
M_a = (12.159 + 3.735\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
12.159 |
| n |
3.735 |
| gf |
0.800 |
| gb |
-0.536 |
| k |
0.800 |
| δ90 |
9.999 |
| 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 |
| 2024-09-03 |
2025-04-05 |
+5.8025 |
+0.079 |
| 2025-04-05 |
2025-04-21 |
-13.4640 |
-2.999 |
| 2025-04-21 |
2025-04-29 |
-20.8594 |
-6.023 |
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) |
| 2026-06-01 00:00 |
01:22:55.10 |
-52:34:53.7 |
HIP 6546 |
11.77 |
| 2026-06-01 12:00 |
01:23:09.95 |
-52:37:35.0 |
HIP 6546 |
11.12 |
| 2026-06-02 00:00 |
01:23:24.64 |
-52:40:18.0 |
HIP 6546 |
11.60 |
| 2026-06-02 12:00 |
01:23:39.17 |
-52:43:02.8 |
HIP 6546 |
13.08 |
| 2026-06-03 00:00 |
01:23:53.51 |
-52:45:49.4 |
HIP 6546 |
15.28 |
| 2026-06-03 12:00 |
01:24:07.69 |
-52:48:37.7 |
HIP 6546 |
17.94 |
| 2026-06-04 00:00 |
01:24:21.69 |
-52:51:27.8 |
HIP 6546 |
20.89 |
| 2026-06-04 12:00 |
01:24:35.52 |
-52:54:19.6 |
HIP 6546 |
24.02 |
| 2026-06-05 00:00 |
01:24:49.17 |
-52:57:13.1 |
HIP 6546 |
27.28 |
| 2026-06-05 12:00 |
01:25:02.64 |
-53:00:08.3 |
HIP 6546 |
30.62 |
| 2026-06-06 00:00 |
01:25:15.94 |
-53:03:05.3 |
HIP 6662 |
29.66 |
| 2026-06-06 12:00 |
01:25:29.05 |
-53:06:03.9 |
HIP 6662 |
26.62 |
| 2026-06-07 00:00 |
01:25:41.98 |
-53:09:04.2 |
HIP 6662 |
23.69 |
| 2026-06-07 12:00 |
01:25:54.72 |
-53:12:06.3 |
HIP 6662 |
20.93 |
| 2026-06-08 00:00 |
01:26:07.28 |
-53:15:10.0 |
HIP 6662 |
18.43 |
| 2026-06-08 12:00 |
01:26:19.65 |
-53:18:15.3 |
HIP 6662 |
16.29 |
| 2026-06-09 00:00 |
01:26:31.82 |
-53:21:22.4 |
HIP 6662 |
14.68 |
| 2026-06-09 12:00 |
01:26:43.81 |
-53:24:31.1 |
HIP 6662 |
13.81 |
| 2026-06-10 00:00 |
01:26:55.61 |
-53:27:41.4 |
HIP 6662 |
13.82 |
| 2026-06-10 12:00 |
01:27:07.21 |
-53:30:53.4 |
HIP 6662 |
14.71 |
| 2026-06-11 00:00 |
01:27:18.61 |
-53:34:07.0 |
HIP 6662 |
16.35 |
| 2026-06-11 12:00 |
01:27:29.81 |
-53:37:22.2 |
HIP 6662 |
18.54 |
| 2026-06-12 00:00 |
01:27:40.82 |
-53:40:39.0 |
HIP 6883 |
20.68 |
| 2026-06-12 12:00 |
01:27:51.62 |
-53:43:57.4 |
HIP 6883 |
23.17 |
| 2026-06-13 00:00 |
01:28:02.22 |
-53:47:17.4 |
HIP 6883 |
25.98 |
| 2026-06-13 12:00 |
01:28:12.61 |
-53:50:38.9 |
HIP 6980 |
23.73 |
| 2026-06-14 00:00 |
01:28:22.79 |
-53:54:02.0 |
HIP 6980 |
20.16 |
| 2026-06-14 12:00 |
01:28:32.77 |
-53:57:26.7 |
HIP 6980 |
16.64 |
| 2026-06-15 00:00 |
01:28:42.53 |
-54:00:52.9 |
HIP 6980 |
13.24 |
| 2026-06-15 12:00 |
01:28:52.08 |
-54:04:20.6 |
HIP 6980 |
10.10 |
| 2026-06-16 00:00 |
01:29:01.41 |
-54:07:49.8 |
HIP 6980 |
7.54 |
| 2026-06-16 12:00 |
01:29:10.52 |
-54:11:20.5 |
HIP 6980 |
6.35 |
| 2026-06-17 00:00 |
01:29:19.42 |
-54:14:52.6 |
HIP 6980 |
7.25 |
| 2026-06-17 12:00 |
01:29:28.09 |
-54:18:26.2 |
HIP 6980 |
9.70 |
| 2026-06-18 00:00 |
01:29:36.55 |
-54:22:01.3 |
HIP 6980 |
12.84 |
| 2026-06-18 12:00 |
01:29:44.77 |
-54:25:37.8 |
HIP 6980 |
16.28 |
| 2026-06-19 00:00 |
01:29:52.77 |
-54:29:15.7 |
HIP 6980 |
19.88 |
| 2026-06-19 12:00 |
01:30:00.55 |
-54:32:55.0 |
HIP 6980 |
23.57 |
| 2026-06-20 00:00 |
01:30:08.09 |
-54:36:35.6 |
HIP 7187 |
22.80 |
| 2026-06-20 12:00 |
01:30:15.40 |
-54:40:17.7 |
HIP 7187 |
20.74 |
| 2026-06-21 00:00 |
01:30:22.48 |
-54:44:01.0 |
HIP 7187 |
19.27 |
| 2026-06-21 12:00 |
01:30:29.32 |
-54:47:45.7 |
HIP 7187 |
18.54 |
| 2026-06-22 00:00 |
01:30:35.93 |
-54:51:31.7 |
HIP 7187 |
18.65 |