メタデータ
| 項目 |
値 |
| Designation |
C/2025 K2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2025-10-25T10:16:18.180480Z |
| Orbit solution date (soln_date, UTC) |
2026-08-07T12:42:15Z |
| Obs used |
30 |
| 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) |
2025-07-21.0000000 |
| e |
0.88579468 |
| q (au) |
2.863118 |
| a (au) |
25.069921 |
| i (deg) |
113.968451 |
| Ω (om, deg) |
113.822985 |
| ω (w, deg) |
232.487973 |
| M (ma, deg) |
359.242857 |
等級
散乱 + 全体線形
$$
M_a = (15.568 + 3.275\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
15.568 |
| n |
3.275 |
| gf |
0.998 |
| gb |
-1.000 |
| k |
0.977 |
| δ90 |
9.955 |
| 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) |
| 2026-09-20 00:00 |
09:20:17.49 |
-28:56:06.6 |
HIP 45842 |
10.26 |
| 2026-09-20 12:00 |
09:20:30.71 |
-28:56:55.3 |
HIP 45842 |
9.46 |
| 2026-09-21 00:00 |
09:20:43.78 |
-28:57:45.1 |
HIP 45842 |
9.60 |
| 2026-09-21 12:00 |
09:20:56.71 |
-28:58:36.1 |
HIP 45842 |
10.63 |
| 2026-09-22 00:00 |
09:21:09.49 |
-28:59:28.1 |
HIP 45842 |
12.30 |
| 2026-09-22 12:00 |
09:21:22.13 |
-29:00:21.3 |
HIP 45805 |
14.19 |
| 2026-09-23 00:00 |
09:21:34.62 |
-29:01:15.6 |
HIP 45805 |
16.22 |
| 2026-09-23 12:00 |
09:21:46.95 |
-29:02:10.9 |
HIP 45834 |
17.92 |
| 2026-09-24 00:00 |
09:21:59.14 |
-29:03:07.4 |
HIP 45834 |
19.58 |
| 2026-09-24 12:00 |
09:22:11.18 |
-29:04:04.9 |
HIP 46026 |
19.40 |
| 2026-09-25 00:00 |
09:22:23.07 |
-29:05:03.4 |
HIP 46026 |
18.49 |
| 2026-09-25 12:00 |
09:22:34.80 |
-29:06:03.0 |
HIP 46026 |
18.00 |
| 2026-09-26 00:00 |
09:22:46.38 |
-29:07:03.6 |
HIP 46026 |
17.95 |
| 2026-09-26 12:00 |
09:22:57.81 |
-29:08:05.2 |
HIP 46026 |
18.33 |
| 2026-09-27 00:00 |
09:23:09.08 |
-29:09:07.8 |
HIP 46127 |
16.20 |
| 2026-09-27 12:00 |
09:23:20.19 |
-29:10:11.5 |
HIP 46127 |
13.69 |
| 2026-09-28 00:00 |
09:23:31.15 |
-29:11:16.1 |
HIP 46127 |
11.29 |
| 2026-09-28 12:00 |
09:23:41.95 |
-29:12:21.6 |
HIP 46127 |
9.05 |
| 2026-09-29 00:00 |
09:23:52.59 |
-29:13:28.2 |
HIP 46127 |
7.11 |
| 2026-09-29 12:00 |
09:24:03.07 |
-29:14:35.6 |
HIP 46127 |
5.72 |
| 2026-09-30 00:00 |
09:24:13.38 |
-29:15:44.0 |
HIP 46127 |
5.31 |
| 2026-09-30 12:00 |
09:24:23.54 |
-29:16:53.4 |
HIP 46127 |
6.05 |
| 2026-10-01 00:00 |
09:24:33.53 |
-29:18:03.6 |
HIP 46127 |
7.58 |
| 2026-10-01 12:00 |
09:24:43.36 |
-29:19:14.8 |
HIP 46127 |
9.52 |
| 2026-10-02 00:00 |
09:24:53.02 |
-29:20:26.8 |
HIP 46127 |
11.64 |
| 2026-10-02 12:00 |
09:25:02.52 |
-29:21:39.7 |
HIP 46127 |
13.85 |
| 2026-10-03 00:00 |
09:25:11.85 |
-29:22:53.5 |
HIP 46127 |
16.10 |
| 2026-10-03 12:00 |
09:25:21.00 |
-29:24:08.2 |
HIP 46291 |
14.19 |
| 2026-10-04 00:00 |
09:25:29.99 |
-29:25:23.7 |
HIP 46291 |
12.07 |
| 2026-10-04 12:00 |
09:25:38.81 |
-29:26:40.0 |
HIP 46291 |
10.09 |
| 2026-10-05 00:00 |
09:25:47.45 |
-29:27:57.1 |
HIP 46291 |
8.31 |
| 2026-10-05 12:00 |
09:25:55.92 |
-29:29:15.0 |
HIP 46291 |
6.88 |
| 2026-10-06 00:00 |
09:26:04.21 |
-29:30:33.7 |
HIP 46291 |
6.02 |
| 2026-10-06 12:00 |
09:26:12.33 |
-29:31:53.2 |
HIP 46291 |
5.96 |
| 2026-10-07 00:00 |
09:26:20.26 |
-29:33:13.4 |
HIP 46291 |
6.69 |
| 2026-10-07 12:00 |
09:26:28.02 |
-29:34:34.4 |
HIP 46291 |
7.98 |
| 2026-10-08 00:00 |
09:26:35.60 |
-29:35:56.1 |
HIP 46291 |
9.59 |
| 2026-10-08 12:00 |
09:26:42.99 |
-29:37:18.6 |
HIP 46291 |
11.37 |
| 2026-10-09 00:00 |
09:26:50.20 |
-29:38:41.7 |
HIP 46291 |
13.25 |
| 2026-10-09 12:00 |
09:26:57.22 |
-29:40:05.5 |
HIP 46291 |
15.17 |
| 2026-10-10 00:00 |
09:27:04.06 |
-29:41:30.0 |
HIP 46291 |
17.12 |
| 2026-10-10 12:00 |
09:27:10.71 |
-29:42:55.1 |
HIP 46291 |
19.07 |
| 2026-10-11 00:00 |
09:27:17.18 |
-29:44:20.8 |
HIP 46291 |
21.03 |