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
$$
M_a = (14.827 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
14.827 |
| n |
6.000 |
| gf |
0.991 |
| 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) |
| 2026-07-29 00:00 |
06:46:19.20 |
-42:26:29.3 |
HIP 32580 |
20.81 |
| 2026-07-29 12:00 |
06:46:30.25 |
-42:27:16.1 |
HIP 32580 |
18.69 |
| 2026-07-30 00:00 |
06:46:41.26 |
-42:28:03.7 |
HIP 32580 |
16.59 |
| 2026-07-30 12:00 |
06:46:52.22 |
-42:28:52.2 |
HIP 32580 |
14.52 |
| 2026-07-31 00:00 |
06:47:03.14 |
-42:29:41.5 |
HIP 32580 |
12.47 |
| 2026-07-31 12:00 |
06:47:14.01 |
-42:30:31.7 |
HIP 32580 |
10.47 |
| 2026-08-01 00:00 |
06:47:24.84 |
-42:31:22.7 |
HIP 32580 |
8.54 |
| 2026-08-01 12:00 |
06:47:35.61 |
-42:32:14.7 |
HIP 32580 |
6.76 |
| 2026-08-02 00:00 |
06:47:46.34 |
-42:33:07.4 |
HIP 32580 |
5.26 |
| 2026-08-02 12:00 |
06:47:57.02 |
-42:34:01.0 |
HIP 32580 |
4.33 |
| 2026-08-03 00:00 |
06:48:07.65 |
-42:34:55.5 |
HIP 32580 |
4.37 |
| 2026-08-03 12:00 |
06:48:18.22 |
-42:35:50.8 |
HIP 32580 |
5.34 |
| 2026-08-04 00:00 |
06:48:28.75 |
-42:36:46.9 |
HIP 32580 |
6.86 |
| 2026-08-04 12:00 |
06:48:39.23 |
-42:37:43.8 |
HIP 32580 |
8.64 |
| 2026-08-05 00:00 |
06:48:49.65 |
-42:38:41.6 |
HIP 32681 |
10.15 |
| 2026-08-05 12:00 |
06:49:00.02 |
-42:39:40.2 |
HIP 32681 |
10.83 |
| 2026-08-06 00:00 |
06:49:10.34 |
-42:40:39.7 |
HIP 32681 |
11.87 |
| 2026-08-06 12:00 |
06:49:20.60 |
-42:41:39.9 |
HIP 32681 |
13.19 |
| 2026-08-07 00:00 |
06:49:30.81 |
-42:42:41.0 |
HIP 32681 |
14.71 |
| 2026-08-07 12:00 |
06:49:40.97 |
-42:43:42.9 |
HIP 32681 |
16.38 |
| 2026-08-08 00:00 |
06:49:51.07 |
-42:44:45.6 |
HIP 32681 |
18.16 |
| 2026-08-08 12:00 |
06:50:01.11 |
-42:45:49.1 |
HIP 32681 |
20.01 |
| 2026-08-09 00:00 |
06:50:11.09 |
-42:46:53.5 |
HIP 32681 |
21.91 |
| 2026-08-09 12:00 |
06:50:21.02 |
-42:47:58.6 |
HIP 32681 |
23.86 |
| 2026-08-10 00:00 |
06:50:30.89 |
-42:49:04.5 |
HIP 32951 |
22.22 |
| 2026-08-10 12:00 |
06:50:40.70 |
-42:50:11.2 |
HIP 32951 |
20.23 |
| 2026-08-11 00:00 |
06:50:50.45 |
-42:51:18.7 |
HIP 32951 |
18.25 |
| 2026-08-11 12:00 |
06:51:00.14 |
-42:52:26.9 |
HIP 32951 |
16.31 |
| 2026-08-12 00:00 |
06:51:09.76 |
-42:53:36.0 |
HIP 32951 |
14.40 |
| 2026-08-12 12:00 |
06:51:19.33 |
-42:54:45.8 |
HIP 32951 |
12.56 |
| 2026-08-13 00:00 |
06:51:28.83 |
-42:55:56.4 |
HIP 32951 |
10.79 |
| 2026-08-13 12:00 |
06:51:38.27 |
-42:57:07.7 |
HIP 32951 |
9.16 |
| 2026-08-14 00:00 |
06:51:47.65 |
-42:58:19.8 |
HIP 32951 |
7.75 |
| 2026-08-14 12:00 |
06:51:56.96 |
-42:59:32.6 |
HIP 32951 |
6.69 |
| 2026-08-15 00:00 |
06:52:06.21 |
-43:00:46.2 |
HIP 32951 |
6.16 |
| 2026-08-15 12:00 |
06:52:15.39 |
-43:02:00.6 |
HIP 32951 |
6.29 |
| 2026-08-16 00:00 |
06:52:24.50 |
-43:03:15.6 |
HIP 32951 |
7.05 |
| 2026-08-16 12:00 |
06:52:33.55 |
-43:04:31.4 |
HIP 32951 |
8.26 |
| 2026-08-17 00:00 |
06:52:42.53 |
-43:05:47.9 |
HIP 32951 |
9.75 |
| 2026-08-17 12:00 |
06:52:51.44 |
-43:07:05.2 |
HIP 33111 |
10.21 |
| 2026-08-18 00:00 |
06:53:00.28 |
-43:08:23.1 |
HIP 33111 |
8.73 |
| 2026-08-18 12:00 |
06:53:09.05 |
-43:09:41.8 |
HIP 33111 |
7.55 |
| 2026-08-19 00:00 |
06:53:17.76 |
-43:11:01.1 |
HIP 33111 |
6.82 |