メタデータ
| 項目 |
値 |
| Designation |
C/2025 K2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2025-10-25T07:48:17.305920Z |
| Orbit solution date (soln_date, UTC) |
2025-08-12T09:42:16Z |
| Obs used |
26 |
| NEO |
- |
| M1 |
7.400 |
| K1 |
21.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2025-05-29T12:48:33.840000Z |
| Discovery magnitude (MPC) |
20.47 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2025-06-09.0000000 |
| e |
0.88709889 |
| q (au) |
2.863643 |
| a (au) |
25.364173 |
| i (deg) |
113.978010 |
| Ω (om, deg) |
113.828014 |
| ω (w, deg) |
232.466816 |
| M (ma, deg) |
358.932730 |
等級
散乱 + 全体線形
$$
M_a = (16.125 + 4.640\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
16.125 |
| n |
4.640 |
| gf |
1.000 |
| gb |
-0.976 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
07:35:11.85 |
-48:19:39.6 |
HIP 36763 |
26.29 |
| 2026-05-12 12:00 |
07:35:39.92 |
-48:06:56.9 |
HIP 36763 |
21.96 |
| 2026-05-13 00:00 |
07:36:08.02 |
-47:54:19.0 |
HIP 37118 |
22.52 |
| 2026-05-13 12:00 |
07:36:36.17 |
-47:41:45.9 |
HIP 37118 |
11.07 |
| 2026-05-14 00:00 |
07:37:04.34 |
-47:29:17.6 |
HIP 37118 |
9.79 |
| 2026-05-14 12:00 |
07:37:32.56 |
-47:16:54.2 |
HIP 37008 |
12.04 |
| 2026-05-15 00:00 |
07:38:00.81 |
-47:04:35.6 |
HIP 37324 |
17.77 |
| 2026-05-15 12:00 |
07:38:29.09 |
-46:52:21.8 |
HIP 37324 |
17.05 |
| 2026-05-16 00:00 |
07:38:57.40 |
-46:40:13.0 |
HIP 37324 |
24.63 |
| 2026-05-16 12:00 |
07:39:25.74 |
-46:28:09.0 |
HIP 37525 |
30.01 |
| 2026-05-17 00:00 |
07:39:54.10 |
-46:16:09.9 |
HIP 37343 |
17.99 |
| 2026-05-17 12:00 |
07:40:22.50 |
-46:04:15.7 |
HIP 37343 |
7.76 |
| 2026-05-18 00:00 |
07:40:50.92 |
-45:52:26.3 |
HIP 37343 |
11.33 |
| 2026-05-18 12:00 |
07:41:19.36 |
-45:40:41.9 |
HIP 37343 |
22.87 |
| 2026-05-19 00:00 |
07:41:47.82 |
-45:29:02.4 |
HIP 37363 |
18.97 |
| 2026-05-19 12:00 |
07:42:16.30 |
-45:17:27.8 |
HIP 37606 |
10.15 |
| 2026-05-20 00:00 |
07:42:44.80 |
-45:05:58.1 |
HIP 37606 |
4.85 |
| 2026-05-20 12:00 |
07:43:13.32 |
-44:54:33.3 |
HIP 37606 |
16.01 |
| 2026-05-21 00:00 |
07:43:41.85 |
-44:43:13.5 |
HIP 37837 |
20.73 |
| 2026-05-21 12:00 |
07:44:10.40 |
-44:31:58.5 |
HIP 37856 |
18.05 |
| 2026-05-22 00:00 |
07:44:38.96 |
-44:20:48.5 |
HIP 37856 |
10.37 |
| 2026-05-22 12:00 |
07:45:07.53 |
-44:09:43.3 |
HIP 37856 |
13.71 |
| 2026-05-23 00:00 |
07:45:36.12 |
-43:58:43.0 |
HIP 37823 |
13.95 |
| 2026-05-23 12:00 |
07:46:04.71 |
-43:47:47.7 |
HIP 37823 |
8.83 |
| 2026-05-24 00:00 |
07:46:33.30 |
-43:36:57.2 |
HIP 37993 |
14.94 |
| 2026-05-24 12:00 |
07:47:01.91 |
-43:26:11.6 |
HIP 37993 |
3.02 |
| 2026-05-25 00:00 |
07:47:30.52 |
-43:15:30.8 |
HIP 37987 |
6.42 |
| 2026-05-25 12:00 |
07:47:59.13 |
-43:04:54.9 |
HIP 38133 |
16.75 |
| 2026-05-26 00:00 |
07:48:27.75 |
-42:54:23.9 |
HIP 38145 |
23.61 |
| 2026-05-26 12:00 |
07:48:56.37 |
-42:43:57.7 |
HIP 38145 |
12.39 |
| 2026-05-27 00:00 |
07:49:24.99 |
-42:33:36.4 |
HIP 38145 |
4.82 |
| 2026-05-27 12:00 |
07:49:53.61 |
-42:23:19.8 |
HIP 38145 |
12.72 |
| 2026-05-28 00:00 |
07:50:22.23 |
-42:13:08.1 |
HIP 38230 |
6.43 |
| 2026-05-28 12:00 |
07:50:50.85 |
-42:03:01.2 |
HIP 38230 |
11.54 |
| 2026-05-29 00:00 |
07:51:19.47 |
-41:52:59.0 |
HIP 38400 |
9.65 |
| 2026-05-29 12:00 |
07:51:48.08 |
-41:43:01.7 |
HIP 38400 |
4.82 |
| 2026-05-30 00:00 |
07:52:16.69 |
-41:33:09.0 |
HIP 38400 |
14.36 |
| 2026-05-30 12:00 |
07:52:45.30 |
-41:23:21.2 |
HIP 38471 |
4.60 |
| 2026-05-31 00:00 |
07:53:13.90 |
-41:13:38.1 |
HIP 38471 |
7.26 |
| 2026-05-31 12:00 |
07:53:42.50 |
-41:03:59.7 |
HIP 38577 |
5.70 |
| 2026-06-01 00:00 |
07:54:11.09 |
-40:54:26.0 |
HIP 38610 |
3.64 |
| 2026-06-01 12:00 |
07:54:39.67 |
-40:44:57.1 |
HIP 38610 |
7.30 |
| 2026-06-02 00:00 |
07:55:08.24 |
-40:35:32.8 |
HIP 38799 |
14.90 |