メタデータ
| 項目 |
値 |
| Designation |
C/2023 A2 (SWAN) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-01-20T09:20:12.062400Z |
| Orbit solution date (soln_date, UTC) |
2026-03-12T09:30:38Z |
| Obs used |
159 |
| NEO |
- |
| M1 |
12.800 |
| K1 |
20.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2023-01-06T00:00:00Z |
| 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) |
2023-03-06.0000000 |
| e |
0.99829132 |
| q (au) |
0.947460 |
| a (au) |
554.499318 |
| i (deg) |
94.708355 |
| Ω (om, deg) |
94.471088 |
| ω (w, deg) |
142.583308 |
| M (ma, deg) |
0.003367 |
等級
散乱 + 全体線形
$$
M_a = (14.826 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
14.826 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-1.000 |
| k |
0.840 |
| 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) |
| 2026-05-12 00:00 |
06:15:02.49 |
-43:43:51.2 |
HIP 29816 |
19.25 |
| 2026-05-12 12:00 |
06:15:12.83 |
-43:42:04.4 |
HIP 29816 |
17.02 |
| 2026-05-13 00:00 |
06:15:23.23 |
-43:40:18.6 |
HIP 29816 |
14.88 |
| 2026-05-13 12:00 |
06:15:33.69 |
-43:38:33.8 |
HIP 29816 |
12.90 |
| 2026-05-14 00:00 |
06:15:44.20 |
-43:36:49.8 |
HIP 29816 |
11.15 |
| 2026-05-14 12:00 |
06:15:54.77 |
-43:35:06.8 |
HIP 29816 |
9.75 |
| 2026-05-15 00:00 |
06:16:05.40 |
-43:33:24.7 |
HIP 29816 |
8.87 |
| 2026-05-15 12:00 |
06:16:16.08 |
-43:31:43.6 |
HIP 29816 |
8.67 |
| 2026-05-16 00:00 |
06:16:26.81 |
-43:30:03.4 |
HIP 29816 |
9.19 |
| 2026-05-16 12:00 |
06:16:37.59 |
-43:28:24.1 |
HIP 29816 |
10.32 |
| 2026-05-17 00:00 |
06:16:48.43 |
-43:26:45.8 |
HIP 29816 |
11.89 |
| 2026-05-17 12:00 |
06:16:59.32 |
-43:25:08.5 |
HIP 29816 |
13.74 |
| 2026-05-18 00:00 |
06:17:10.26 |
-43:23:32.1 |
HIP 29816 |
15.78 |
| 2026-05-18 12:00 |
06:17:21.25 |
-43:21:56.7 |
HIP 29816 |
17.94 |
| 2026-05-19 00:00 |
06:17:32.29 |
-43:20:22.2 |
HIP 29816 |
20.18 |
| 2026-05-19 12:00 |
06:17:43.38 |
-43:18:48.7 |
HIP 30017 |
21.64 |
| 2026-05-20 00:00 |
06:17:54.51 |
-43:17:16.2 |
HIP 30017 |
21.67 |
| 2026-05-20 12:00 |
06:18:05.69 |
-43:15:44.7 |
HIP 30017 |
21.98 |
| 2026-05-21 00:00 |
06:18:16.92 |
-43:14:14.1 |
HIP 30084 |
21.65 |
| 2026-05-21 12:00 |
06:18:28.19 |
-43:12:44.5 |
HIP 30084 |
19.11 |
| 2026-05-22 00:00 |
06:18:39.51 |
-43:11:15.9 |
HIP 30084 |
16.58 |
| 2026-05-22 12:00 |
06:18:50.87 |
-43:09:48.2 |
HIP 30084 |
14.06 |
| 2026-05-23 00:00 |
06:19:02.27 |
-43:08:21.6 |
HIP 30084 |
11.54 |
| 2026-05-23 12:00 |
06:19:13.71 |
-43:06:55.9 |
HIP 30084 |
9.03 |
| 2026-05-24 00:00 |
06:19:25.19 |
-43:05:31.2 |
HIP 30084 |
6.55 |
| 2026-05-24 12:00 |
06:19:36.72 |
-43:04:07.5 |
HIP 30084 |
4.13 |
| 2026-05-25 00:00 |
06:19:48.28 |
-43:02:44.8 |
HIP 30084 |
2.02 |
| 2026-05-25 12:00 |
06:19:59.88 |
-43:01:23.1 |
HIP 30084 |
1.96 |
| 2026-05-26 00:00 |
06:20:11.52 |
-43:00:02.3 |
HIP 30084 |
4.05 |
| 2026-05-26 12:00 |
06:20:23.20 |
-42:58:42.6 |
HIP 30084 |
6.45 |
| 2026-05-27 00:00 |
06:20:34.91 |
-42:57:23.8 |
HIP 30084 |
8.92 |
| 2026-05-27 12:00 |
06:20:46.66 |
-42:56:06.1 |
HIP 30084 |
11.40 |
| 2026-05-28 00:00 |
06:20:58.45 |
-42:54:49.3 |
HIP 30084 |
13.90 |
| 2026-05-28 12:00 |
06:21:10.27 |
-42:53:33.5 |
HIP 30084 |
16.40 |
| 2026-05-29 00:00 |
06:21:22.12 |
-42:52:18.8 |
HIP 30077 |
18.74 |
| 2026-05-29 12:00 |
06:21:34.01 |
-42:51:05.0 |
HIP 30077 |
20.38 |
| 2026-05-30 00:00 |
06:21:45.93 |
-42:49:52.2 |
HIP 30077 |
22.20 |
| 2026-05-30 12:00 |
06:21:57.88 |
-42:48:40.4 |
HIP 30077 |
24.15 |
| 2026-05-31 00:00 |
06:22:09.86 |
-42:47:29.7 |
HIP 30476 |
24.92 |
| 2026-05-31 12:00 |
06:22:21.87 |
-42:46:19.9 |
HIP 30476 |
22.95 |
| 2026-06-01 00:00 |
06:22:33.92 |
-42:45:11.1 |
HIP 30476 |
21.08 |
| 2026-06-01 12:00 |
06:22:45.99 |
-42:44:03.3 |
HIP 30476 |
19.33 |
| 2026-06-02 00:00 |
06:22:58.09 |
-42:42:56.6 |
HIP 30476 |
17.75 |