メタデータ
| 項目 |
値 |
| Designation |
C/2025 A4 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2025-01-13T02:45:57.608640Z |
| Orbit solution date (soln_date, UTC) |
2025-06-26T10:13:11Z |
| Obs used |
100 |
| NEO |
- |
| M1 |
15.400 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2025-01-03T15:06:00.892800Z |
| Discovery magnitude (MPC) |
21.05 w |
| Discovery observatory (MPC) |
F52 · Pan-STARRS 2, Haleakala |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2025-03-05.0000000 |
| e |
0.65381554 |
| q (au) |
3.824179 |
| a (au) |
11.046652 |
| i (deg) |
32.025692 |
| Ω (om, deg) |
69.912504 |
| ω (w, deg) |
102.791064 |
| M (ma, deg) |
1.365984 |
等級
散乱 + 全体線形
$$
M_a = (14.631 + 3.439\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
14.631 |
| n |
3.439 |
| gf |
1.000 |
| gb |
-0.628 |
| k |
0.800 |
| 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
ファインディングチャート
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
16:01:25.59 |
-15:16:16.2 |
HIP 78503 |
3.90 |
| 2026-06-01 12:00 |
16:01:07.98 |
-15:17:25.0 |
HIP 78503 |
7.94 |
| 2026-06-02 00:00 |
16:00:50.42 |
-15:18:34.0 |
HIP 78430 |
6.44 |
| 2026-06-02 12:00 |
16:00:32.93 |
-15:19:43.2 |
HIP 78430 |
5.56 |
| 2026-06-03 00:00 |
16:00:15.51 |
-15:20:52.7 |
HIP 78430 |
7.64 |
| 2026-06-03 12:00 |
15:59:58.15 |
-15:22:02.4 |
HIP 78430 |
11.11 |
| 2026-06-04 00:00 |
15:59:40.86 |
-15:23:12.4 |
HIP 78430 |
15.02 |
| 2026-06-04 12:00 |
15:59:23.64 |
-15:24:22.6 |
HIP 78239 |
15.96 |
| 2026-06-05 00:00 |
15:59:06.49 |
-15:25:33.0 |
HIP 78211 |
12.77 |
| 2026-06-05 12:00 |
15:58:49.43 |
-15:26:43.7 |
HIP 78211 |
8.49 |
| 2026-06-06 00:00 |
15:58:32.44 |
-15:27:54.6 |
HIP 78211 |
4.24 |
| 2026-06-06 12:00 |
15:58:15.53 |
-15:29:05.8 |
HIP 78211 |
0.44 |
| 2026-06-07 00:00 |
15:57:58.71 |
-15:30:17.2 |
HIP 78211 |
4.27 |
| 2026-06-07 12:00 |
15:57:41.97 |
-15:31:28.8 |
HIP 78211 |
8.46 |
| 2026-06-08 00:00 |
15:57:25.33 |
-15:32:40.8 |
HIP 78115 |
6.72 |
| 2026-06-08 12:00 |
15:57:08.77 |
-15:33:52.9 |
HIP 78115 |
5.37 |
| 2026-06-09 00:00 |
15:56:52.32 |
-15:35:05.3 |
HIP 78115 |
6.86 |
| 2026-06-09 12:00 |
15:56:35.95 |
-15:36:18.0 |
HIP 78115 |
9.97 |
| 2026-06-10 00:00 |
15:56:19.69 |
-15:37:31.0 |
HIP 78115 |
13.62 |
| 2026-06-10 12:00 |
15:56:03.53 |
-15:38:44.2 |
HIP 78115 |
17.45 |
| 2026-06-11 00:00 |
15:55:47.47 |
-15:39:57.6 |
HIP 78115 |
21.35 |
| 2026-06-11 12:00 |
15:55:31.52 |
-15:41:11.3 |
HIP 77874 |
19.61 |
| 2026-06-12 00:00 |
15:55:15.68 |
-15:42:25.3 |
HIP 77874 |
15.95 |
| 2026-06-12 12:00 |
15:54:59.95 |
-15:43:39.6 |
HIP 77874 |
12.55 |
| 2026-06-13 00:00 |
15:54:44.33 |
-15:44:54.1 |
HIP 77874 |
9.62 |
| 2026-06-13 12:00 |
15:54:28.83 |
-15:46:09.0 |
HIP 77874 |
7.71 |
| 2026-06-14 00:00 |
15:54:13.45 |
-15:47:24.0 |
HIP 77874 |
7.57 |
| 2026-06-14 12:00 |
15:53:58.19 |
-15:48:39.4 |
HIP 77874 |
9.25 |
| 2026-06-15 00:00 |
15:53:43.05 |
-15:49:55.1 |
HIP 77874 |
11.99 |
| 2026-06-15 12:00 |
15:53:28.04 |
-15:51:11.0 |
HIP 77874 |
15.20 |
| 2026-06-16 00:00 |
15:53:13.15 |
-15:52:27.2 |
HIP 77874 |
18.63 |
| 2026-06-16 12:00 |
15:52:58.40 |
-15:53:43.7 |
HIP 77874 |
22.15 |
| 2026-06-17 00:00 |
15:52:43.78 |
-15:55:00.5 |
HIP 77663 |
23.13 |
| 2026-06-17 12:00 |
15:52:29.29 |
-15:56:17.6 |
HIP 77663 |
20.71 |
| 2026-06-18 00:00 |
15:52:14.94 |
-15:57:34.9 |
HIP 77663 |
18.74 |
| 2026-06-18 12:00 |
15:52:00.72 |
-15:58:52.6 |
HIP 77663 |
17.37 |
| 2026-06-19 00:00 |
15:51:46.65 |
-16:00:10.5 |
HIP 77663 |
16.72 |
| 2026-06-19 12:00 |
15:51:32.72 |
-16:01:28.7 |
HIP 77663 |
16.86 |
| 2026-06-20 00:00 |
15:51:18.93 |
-16:02:47.3 |
HIP 77663 |
17.75 |
| 2026-06-20 12:00 |
15:51:05.28 |
-16:04:06.1 |
HIP 77663 |
19.26 |
| 2026-06-21 00:00 |
15:50:51.79 |
-16:05:25.2 |
HIP 77663 |
21.25 |
| 2026-06-21 12:00 |
15:50:38.44 |
-16:06:44.6 |
HIP 77663 |
23.59 |
| 2026-06-22 00:00 |
15:50:25.24 |
-16:08:04.3 |
HIP 77663 |
26.17 |