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) |
| 2026-09-20 00:00 |
15:58:26.25 |
-21:17:34.7 |
HIP 78233 |
6.52 |
| 2026-09-20 12:00 |
15:58:43.05 |
-21:19:31.7 |
HIP 78233 |
5.55 |
| 2026-09-21 00:00 |
15:58:59.97 |
-21:21:28.6 |
HIP 78233 |
7.59 |
| 2026-09-21 12:00 |
15:59:17.00 |
-21:23:25.6 |
HIP 78233 |
11.12 |
| 2026-09-22 00:00 |
15:59:34.14 |
-21:25:22.6 |
HIP 78233 |
15.14 |
| 2026-09-22 12:00 |
15:59:51.39 |
-21:27:19.5 |
HIP 78233 |
19.38 |
| 2026-09-23 00:00 |
16:00:08.75 |
-21:29:16.5 |
HIP 78233 |
23.72 |
| 2026-09-23 12:00 |
16:00:26.22 |
-21:31:13.4 |
HIP 78467 |
23.75 |
| 2026-09-24 00:00 |
16:00:43.80 |
-21:33:10.3 |
HIP 78467 |
24.38 |
| 2026-09-24 12:00 |
16:01:01.49 |
-21:35:07.3 |
HIP 78467 |
25.80 |
| 2026-09-25 00:00 |
16:01:19.29 |
-21:37:04.1 |
HIP 78530 |
23.32 |
| 2026-09-25 12:00 |
16:01:37.19 |
-21:39:01.0 |
HIP 78530 |
20.25 |
| 2026-09-26 00:00 |
16:01:55.20 |
-21:40:57.8 |
HIP 78530 |
17.86 |
| 2026-09-26 12:00 |
16:02:13.31 |
-21:42:54.6 |
HIP 78530 |
16.44 |
| 2026-09-27 00:00 |
16:02:31.53 |
-21:44:51.4 |
HIP 78530 |
16.28 |
| 2026-09-27 12:00 |
16:02:49.85 |
-21:46:48.1 |
HIP 78530 |
17.42 |
| 2026-09-28 00:00 |
16:03:08.27 |
-21:48:44.8 |
HIP 78708 |
14.46 |
| 2026-09-28 12:00 |
16:03:26.80 |
-21:50:41.5 |
HIP 78708 |
9.76 |
| 2026-09-29 00:00 |
16:03:45.42 |
-21:52:38.1 |
HIP 78708 |
5.07 |
| 2026-09-29 12:00 |
16:04:04.15 |
-21:54:34.7 |
HIP 78708 |
1.10 |
| 2026-09-30 00:00 |
16:04:22.98 |
-21:56:31.3 |
HIP 78708 |
4.71 |
| 2026-09-30 12:00 |
16:04:41.90 |
-21:58:27.8 |
HIP 78708 |
9.45 |
| 2026-10-01 00:00 |
16:05:00.93 |
-22:00:24.2 |
HIP 78847 |
14.09 |
| 2026-10-01 12:00 |
16:05:20.05 |
-22:02:20.6 |
HIP 78847 |
13.18 |
| 2026-10-02 00:00 |
16:05:39.27 |
-22:04:17.0 |
HIP 78847 |
13.99 |
| 2026-10-02 12:00 |
16:05:58.59 |
-22:06:13.3 |
HIP 78847 |
16.28 |
| 2026-10-03 00:00 |
16:06:18.01 |
-22:08:09.5 |
HIP 78977 |
14.58 |
| 2026-10-03 12:00 |
16:06:37.51 |
-22:10:05.7 |
HIP 78977 |
11.36 |
| 2026-10-04 00:00 |
16:06:57.12 |
-22:12:01.8 |
HIP 78977 |
9.69 |
| 2026-10-04 12:00 |
16:07:16.82 |
-22:13:57.9 |
HIP 78977 |
10.36 |
| 2026-10-05 00:00 |
16:07:36.61 |
-22:15:53.9 |
HIP 78977 |
13.04 |
| 2026-10-05 12:00 |
16:07:56.49 |
-22:17:49.8 |
HIP 78977 |
16.81 |
| 2026-10-06 00:00 |
16:08:16.47 |
-22:19:45.6 |
HIP 78977 |
21.11 |
| 2026-10-06 12:00 |
16:08:36.54 |
-22:21:41.4 |
HIP 78977 |
25.68 |
| 2026-10-07 00:00 |
16:08:56.70 |
-22:23:37.1 |
HIP 79252 |
23.48 |
| 2026-10-07 12:00 |
16:09:16.94 |
-22:25:32.8 |
HIP 79252 |
20.37 |
| 2026-10-08 00:00 |
16:09:37.28 |
-22:27:28.3 |
HIP 79252 |
18.15 |
| 2026-10-08 12:00 |
16:09:57.71 |
-22:29:23.8 |
HIP 79252 |
17.19 |
| 2026-10-09 00:00 |
16:10:18.22 |
-22:31:19.2 |
HIP 79252 |
17.70 |
| 2026-10-09 12:00 |
16:10:38.82 |
-22:33:14.5 |
HIP 79366 |
17.06 |
| 2026-10-10 00:00 |
16:10:59.50 |
-22:35:09.7 |
HIP 79366 |
12.52 |
| 2026-10-10 12:00 |
16:11:20.27 |
-22:37:04.8 |
HIP 79366 |
8.67 |
| 2026-10-11 00:00 |
16:11:41.13 |
-22:38:59.9 |
HIP 79366 |
6.84 |