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) |
| 2026-07-29 00:00 |
15:42:13.77 |
-18:00:13.1 |
HIP 76779 |
23.76 |
| 2026-07-29 12:00 |
15:42:14.15 |
-18:01:55.0 |
HIP 76779 |
23.72 |
| 2026-07-30 00:00 |
15:42:14.71 |
-18:03:37.1 |
HIP 76779 |
23.84 |
| 2026-07-30 12:00 |
15:42:15.46 |
-18:05:19.5 |
HIP 76779 |
24.12 |
| 2026-07-31 00:00 |
15:42:16.40 |
-18:07:02.1 |
HIP 76779 |
24.56 |
| 2026-07-31 12:00 |
15:42:17.52 |
-18:08:45.0 |
HIP 76779 |
25.16 |
| 2026-08-01 00:00 |
15:42:18.83 |
-18:10:28.1 |
HIP 76779 |
25.91 |
| 2026-08-01 12:00 |
15:42:20.32 |
-18:12:11.5 |
HIP 76937 |
24.60 |
| 2026-08-02 00:00 |
15:42:22.00 |
-18:13:55.1 |
HIP 76937 |
22.83 |
| 2026-08-02 12:00 |
15:42:23.86 |
-18:15:39.0 |
HIP 76937 |
21.05 |
| 2026-08-03 00:00 |
15:42:25.90 |
-18:17:23.2 |
HIP 76937 |
19.26 |
| 2026-08-03 12:00 |
15:42:28.13 |
-18:19:07.5 |
HIP 76937 |
17.46 |
| 2026-08-04 00:00 |
15:42:30.54 |
-18:20:52.2 |
HIP 76937 |
15.66 |
| 2026-08-04 12:00 |
15:42:33.13 |
-18:22:37.0 |
HIP 76937 |
13.86 |
| 2026-08-05 00:00 |
15:42:35.90 |
-18:24:22.2 |
HIP 76937 |
12.07 |
| 2026-08-05 12:00 |
15:42:38.86 |
-18:26:07.5 |
HIP 76937 |
10.30 |
| 2026-08-06 00:00 |
15:42:41.99 |
-18:27:53.1 |
HIP 76937 |
8.59 |
| 2026-08-06 12:00 |
15:42:45.31 |
-18:29:38.9 |
HIP 76937 |
6.99 |
| 2026-08-07 00:00 |
15:42:48.81 |
-18:31:25.0 |
HIP 76937 |
5.61 |
| 2026-08-07 12:00 |
15:42:52.48 |
-18:33:11.3 |
HIP 76937 |
4.70 |
| 2026-08-08 00:00 |
15:42:56.34 |
-18:34:57.8 |
HIP 76937 |
4.56 |
| 2026-08-08 12:00 |
15:43:00.38 |
-18:36:44.6 |
HIP 76937 |
5.29 |
| 2026-08-09 00:00 |
15:43:04.59 |
-18:38:31.6 |
HIP 76937 |
6.62 |
| 2026-08-09 12:00 |
15:43:08.99 |
-18:40:18.8 |
HIP 76937 |
8.29 |
| 2026-08-10 00:00 |
15:43:13.56 |
-18:42:06.3 |
HIP 76937 |
10.14 |
| 2026-08-10 12:00 |
15:43:18.31 |
-18:43:53.9 |
HIP 76937 |
12.11 |
| 2026-08-11 00:00 |
15:43:23.24 |
-18:45:41.8 |
HIP 76937 |
14.15 |
| 2026-08-11 12:00 |
15:43:28.34 |
-18:47:29.9 |
HIP 76937 |
16.25 |
| 2026-08-12 00:00 |
15:43:33.62 |
-18:49:18.3 |
HIP 76937 |
18.41 |
| 2026-08-12 12:00 |
15:43:39.07 |
-18:51:06.8 |
HIP 77124 |
18.57 |
| 2026-08-13 00:00 |
15:43:44.70 |
-18:52:55.6 |
HIP 77124 |
18.03 |
| 2026-08-13 12:00 |
15:43:50.51 |
-18:54:44.5 |
HIP 77124 |
17.73 |
| 2026-08-14 00:00 |
15:43:56.48 |
-18:56:33.7 |
HIP 77124 |
17.69 |
| 2026-08-14 12:00 |
15:44:02.63 |
-18:58:23.1 |
HIP 77124 |
17.92 |
| 2026-08-15 00:00 |
15:44:08.96 |
-19:00:12.6 |
HIP 77124 |
18.43 |
| 2026-08-15 12:00 |
15:44:15.45 |
-19:02:02.4 |
HIP 77165 |
16.75 |
| 2026-08-16 00:00 |
15:44:22.11 |
-19:03:52.4 |
HIP 77165 |
14.81 |
| 2026-08-16 12:00 |
15:44:28.95 |
-19:05:42.6 |
HIP 77165 |
12.99 |
| 2026-08-17 00:00 |
15:44:35.95 |
-19:07:32.9 |
HIP 77165 |
11.37 |
| 2026-08-17 12:00 |
15:44:43.12 |
-19:09:23.5 |
HIP 77165 |
10.06 |
| 2026-08-18 00:00 |
15:44:50.46 |
-19:11:14.2 |
HIP 77165 |
9.23 |
| 2026-08-18 12:00 |
15:44:57.97 |
-19:13:05.1 |
HIP 77165 |
9.03 |
| 2026-08-19 00:00 |
15:45:05.64 |
-19:14:56.2 |
HIP 77165 |
9.53 |