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 |
0.993 |
| 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) |
| 2026-07-29 00:00 |
08:46:09.92 |
-30:01:39.2 |
HIP 43088 |
17.04 |
| 2026-07-29 12:00 |
08:46:33.90 |
-29:59:13.7 |
HIP 43088 |
13.73 |
| 2026-07-30 00:00 |
08:46:57.81 |
-29:56:50.7 |
HIP 43088 |
12.38 |
| 2026-07-30 12:00 |
08:47:21.65 |
-29:54:30.2 |
HIP 43088 |
13.55 |
| 2026-07-31 00:00 |
08:47:45.43 |
-29:52:12.2 |
HIP 43088 |
16.69 |
| 2026-07-31 12:00 |
08:48:09.13 |
-29:49:56.8 |
HIP 43088 |
20.91 |
| 2026-08-01 00:00 |
08:48:32.77 |
-29:47:43.8 |
HIP 43093 |
25.59 |
| 2026-08-01 12:00 |
08:48:56.33 |
-29:45:33.3 |
HIP 43370 |
22.83 |
| 2026-08-02 00:00 |
08:49:19.83 |
-29:43:25.3 |
HIP 43370 |
18.16 |
| 2026-08-02 12:00 |
08:49:43.25 |
-29:41:19.7 |
HIP 43370 |
14.16 |
| 2026-08-03 00:00 |
08:50:06.60 |
-29:39:16.6 |
HIP 43370 |
11.54 |
| 2026-08-03 12:00 |
08:50:29.88 |
-29:37:15.9 |
HIP 43370 |
11.23 |
| 2026-08-04 00:00 |
08:50:53.08 |
-29:35:17.6 |
HIP 43370 |
13.37 |
| 2026-08-04 12:00 |
08:51:16.22 |
-29:33:21.6 |
HIP 43517 |
8.86 |
| 2026-08-05 00:00 |
08:51:39.28 |
-29:31:28.1 |
HIP 43517 |
4.10 |
| 2026-08-05 12:00 |
08:52:02.26 |
-29:29:36.9 |
HIP 43517 |
3.55 |
| 2026-08-06 00:00 |
08:52:25.17 |
-29:27:48.1 |
HIP 43517 |
8.06 |
| 2026-08-06 12:00 |
08:52:48.01 |
-29:26:01.6 |
HIP 43517 |
13.16 |
| 2026-08-07 00:00 |
08:53:10.77 |
-29:24:17.4 |
HIP 43517 |
18.34 |
| 2026-08-07 12:00 |
08:53:33.45 |
-29:22:35.5 |
HIP 43517 |
23.53 |
| 2026-08-08 00:00 |
08:53:56.06 |
-29:20:55.9 |
HIP 43517 |
28.71 |
| 2026-08-08 12:00 |
08:54:18.59 |
-29:19:18.7 |
HIP 43877 |
27.36 |
| 2026-08-09 00:00 |
08:54:41.04 |
-29:17:43.6 |
HIP 43877 |
23.31 |
| 2026-08-09 12:00 |
08:55:03.41 |
-29:16:10.9 |
HIP 43890 |
19.14 |
| 2026-08-10 00:00 |
08:55:25.70 |
-29:14:40.4 |
HIP 43890 |
15.01 |
| 2026-08-10 12:00 |
08:55:47.92 |
-29:13:12.1 |
HIP 43890 |
11.64 |
| 2026-08-11 00:00 |
08:56:10.05 |
-29:11:46.0 |
HIP 43890 |
9.82 |
| 2026-08-11 12:00 |
08:56:32.10 |
-29:10:22.1 |
HIP 43890 |
10.36 |
| 2026-08-12 00:00 |
08:56:54.07 |
-29:09:00.5 |
HIP 43890 |
12.94 |
| 2026-08-12 12:00 |
08:57:15.95 |
-29:07:40.9 |
HIP 43890 |
16.61 |
| 2026-08-13 00:00 |
08:57:37.75 |
-29:06:23.6 |
HIP 44028 |
14.83 |
| 2026-08-13 12:00 |
08:57:59.47 |
-29:05:08.4 |
HIP 44028 |
12.88 |
| 2026-08-14 00:00 |
08:58:21.10 |
-29:03:55.3 |
HIP 44028 |
12.69 |
| 2026-08-14 12:00 |
08:58:42.64 |
-29:02:44.3 |
HIP 44028 |
14.28 |
| 2026-08-15 00:00 |
08:59:04.10 |
-29:01:35.4 |
HIP 44130 |
13.47 |
| 2026-08-15 12:00 |
08:59:25.47 |
-29:00:28.6 |
HIP 44196 |
11.00 |
| 2026-08-16 00:00 |
08:59:46.75 |
-28:59:23.8 |
HIP 44196 |
8.04 |
| 2026-08-16 12:00 |
09:00:07.94 |
-28:58:21.1 |
HIP 44196 |
7.31 |
| 2026-08-17 00:00 |
09:00:29.04 |
-28:57:20.5 |
HIP 44196 |
9.30 |
| 2026-08-17 12:00 |
09:00:50.06 |
-28:56:21.8 |
HIP 44196 |
12.78 |
| 2026-08-18 00:00 |
09:01:10.98 |
-28:55:25.2 |
HIP 44196 |
16.82 |
| 2026-08-18 12:00 |
09:01:31.80 |
-28:54:30.5 |
HIP 44362 |
18.24 |
| 2026-08-19 00:00 |
09:01:52.54 |
-28:53:37.9 |
HIP 44362 |
17.95 |