メタデータ
| 項目 |
値 |
| Designation |
C/2015 K2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-06-08T19:07:06.248640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:11Z |
| Obs used |
54 |
| NEO |
- |
| M1 |
20.700 |
| K1 |
10.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2015-05-26.0000000 |
| e |
0.99444359 |
| q (au) |
1.455282 |
| a (au) |
261.910605 |
| i (deg) |
29.110346 |
| Ω (om, deg) |
223.713883 |
| ω (w, deg) |
15.770089 |
| M (ma, deg) |
359.996792 |
等級
散乱 + 全体線形
$$
M_a = (20.000 + 3.100\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
20.000 |
| n |
3.100 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| 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 |
02:02:54.94 |
+17:55:07.6 |
HIP 9449 |
20.23 |
| 2026-05-12 12:00 |
02:02:59.31 |
+17:55:30.0 |
HIP 9449 |
21.23 |
| 2026-05-13 00:00 |
02:03:03.68 |
+17:55:52.3 |
HIP 9627 |
21.43 |
| 2026-05-13 12:00 |
02:03:08.03 |
+17:56:14.6 |
HIP 9627 |
20.66 |
| 2026-05-14 00:00 |
02:03:12.37 |
+17:56:36.8 |
HIP 9627 |
19.93 |
| 2026-05-14 12:00 |
02:03:16.69 |
+17:56:59.1 |
HIP 9627 |
19.23 |
| 2026-05-15 00:00 |
02:03:21.01 |
+17:57:21.3 |
HIP 9627 |
18.57 |
| 2026-05-15 12:00 |
02:03:25.31 |
+17:57:43.5 |
HIP 9627 |
17.95 |
| 2026-05-16 00:00 |
02:03:29.60 |
+17:58:05.7 |
HIP 9627 |
17.38 |
| 2026-05-16 12:00 |
02:03:33.87 |
+17:58:27.9 |
HIP 9627 |
16.86 |
| 2026-05-17 00:00 |
02:03:38.14 |
+17:58:50.0 |
HIP 9627 |
16.40 |
| 2026-05-17 12:00 |
02:03:42.39 |
+17:59:12.1 |
HIP 9627 |
16.00 |
| 2026-05-18 00:00 |
02:03:46.62 |
+17:59:34.2 |
HIP 9627 |
15.66 |
| 2026-05-18 12:00 |
02:03:50.84 |
+17:59:56.2 |
HIP 9627 |
15.39 |
| 2026-05-19 00:00 |
02:03:55.05 |
+18:00:18.2 |
HIP 9627 |
15.18 |
| 2026-05-19 12:00 |
02:03:59.24 |
+18:00:40.2 |
HIP 9627 |
15.05 |
| 2026-05-20 00:00 |
02:04:03.42 |
+18:01:02.1 |
HIP 9627 |
15.00 |
| 2026-05-20 12:00 |
02:04:07.58 |
+18:01:24.0 |
HIP 9627 |
15.02 |
| 2026-05-21 00:00 |
02:04:11.73 |
+18:01:45.9 |
HIP 9627 |
15.11 |
| 2026-05-21 12:00 |
02:04:15.86 |
+18:02:07.7 |
HIP 9627 |
15.27 |
| 2026-05-22 00:00 |
02:04:19.97 |
+18:02:29.5 |
HIP 9627 |
15.50 |
| 2026-05-22 12:00 |
02:04:24.07 |
+18:02:51.2 |
HIP 9627 |
15.79 |
| 2026-05-23 00:00 |
02:04:28.15 |
+18:03:12.9 |
HIP 9627 |
16.14 |
| 2026-05-23 12:00 |
02:04:32.22 |
+18:03:34.5 |
HIP 9627 |
16.55 |
| 2026-05-24 00:00 |
02:04:36.27 |
+18:03:56.1 |
HIP 9627 |
17.01 |
| 2026-05-24 12:00 |
02:04:40.30 |
+18:04:17.6 |
HIP 9627 |
17.51 |
| 2026-05-25 00:00 |
02:04:44.31 |
+18:04:39.1 |
HIP 9627 |
18.06 |
| 2026-05-25 12:00 |
02:04:48.31 |
+18:05:00.5 |
HIP 9627 |
18.64 |
| 2026-05-26 00:00 |
02:04:52.29 |
+18:05:21.9 |
HIP 9627 |
19.25 |
| 2026-05-26 12:00 |
02:04:56.25 |
+18:05:43.2 |
HIP 9627 |
19.89 |
| 2026-05-27 00:00 |
02:05:00.19 |
+18:06:04.5 |
HIP 9627 |
20.56 |
| 2026-05-27 12:00 |
02:05:04.11 |
+18:06:25.7 |
HIP 9627 |
21.25 |
| 2026-05-28 00:00 |
02:05:08.02 |
+18:06:46.9 |
HIP 9627 |
21.96 |
| 2026-05-28 12:00 |
02:05:11.90 |
+18:07:08.0 |
HIP 9627 |
22.69 |
| 2026-05-29 00:00 |
02:05:15.77 |
+18:07:29.0 |
HIP 9627 |
23.43 |
| 2026-05-29 12:00 |
02:05:19.62 |
+18:07:50.0 |
HIP 9627 |
24.19 |
| 2026-05-30 00:00 |
02:05:23.45 |
+18:08:10.9 |
HIP 9627 |
24.95 |
| 2026-05-30 12:00 |
02:05:27.25 |
+18:08:31.8 |
HIP 9824 |
25.00 |
| 2026-05-31 00:00 |
02:05:31.04 |
+18:08:52.5 |
HIP 9824 |
24.20 |
| 2026-05-31 12:00 |
02:05:34.81 |
+18:09:13.3 |
HIP 9824 |
23.42 |
| 2026-06-01 00:00 |
02:05:38.56 |
+18:09:33.9 |
HIP 9824 |
22.66 |
| 2026-06-01 12:00 |
02:05:42.29 |
+18:09:54.5 |
HIP 9824 |
21.91 |
| 2026-06-02 00:00 |
02:05:45.99 |
+18:10:15.0 |
HIP 9824 |
21.19 |