メタデータ
| 項目 |
値 |
| Designation |
C/1999 K2 (Ferris) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1999-04-10T12:51:40.688640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:00Z |
| Obs used |
101 |
| NEO |
- |
| M1 |
7.000 |
| 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) |
1999-06-24.0000000 |
| e |
0.96579603 |
| q (au) |
5.290256 |
| a (au) |
154.667896 |
| i (deg) |
82.190925 |
| Ω (om, deg) |
300.318118 |
| ω (w, deg) |
4.570397 |
| M (ma, deg) |
0.038155 |
等級
散乱 + 全体線形
$$
M_a = (12.566 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
12.566 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.664 |
| 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 |
08:18:12.27 |
+52:56:02.5 |
HIP 40602 |
7.51 |
| 2026-05-12 12:00 |
08:18:13.58 |
+52:55:36.7 |
HIP 40602 |
7.70 |
| 2026-05-13 00:00 |
08:18:14.92 |
+52:55:10.9 |
HIP 40602 |
7.91 |
| 2026-05-13 12:00 |
08:18:16.30 |
+52:54:45.1 |
HIP 40602 |
8.15 |
| 2026-05-14 00:00 |
08:18:17.71 |
+52:54:19.4 |
HIP 40602 |
8.42 |
| 2026-05-14 12:00 |
08:18:19.15 |
+52:53:53.6 |
HIP 40602 |
8.70 |
| 2026-05-15 00:00 |
08:18:20.63 |
+52:53:27.8 |
HIP 40602 |
9.01 |
| 2026-05-15 12:00 |
08:18:22.14 |
+52:53:02.1 |
HIP 40602 |
9.34 |
| 2026-05-16 00:00 |
08:18:23.68 |
+52:52:36.4 |
HIP 40602 |
9.69 |
| 2026-05-16 12:00 |
08:18:25.25 |
+52:52:10.7 |
HIP 40602 |
10.05 |
| 2026-05-17 00:00 |
08:18:26.86 |
+52:51:45.0 |
HIP 40602 |
10.43 |
| 2026-05-17 12:00 |
08:18:28.50 |
+52:51:19.3 |
HIP 40602 |
10.82 |
| 2026-05-18 00:00 |
08:18:30.17 |
+52:50:53.7 |
HIP 40602 |
11.23 |
| 2026-05-18 12:00 |
08:18:31.87 |
+52:50:28.1 |
HIP 40602 |
11.64 |
| 2026-05-19 00:00 |
08:18:33.60 |
+52:50:02.5 |
HIP 40602 |
12.07 |
| 2026-05-19 12:00 |
08:18:35.37 |
+52:49:37.0 |
HIP 40602 |
12.51 |
| 2026-05-20 00:00 |
08:18:37.16 |
+52:49:11.4 |
HIP 40602 |
12.95 |
| 2026-05-20 12:00 |
08:18:38.99 |
+52:48:45.9 |
HIP 40602 |
13.40 |
| 2026-05-21 00:00 |
08:18:40.85 |
+52:48:20.5 |
HIP 40602 |
13.86 |
| 2026-05-21 12:00 |
08:18:42.74 |
+52:47:55.1 |
HIP 40602 |
14.33 |
| 2026-05-22 00:00 |
08:18:44.66 |
+52:47:29.7 |
HIP 40602 |
14.80 |
| 2026-05-22 12:00 |
08:18:46.61 |
+52:47:04.3 |
HIP 40602 |
15.28 |
| 2026-05-23 00:00 |
08:18:48.59 |
+52:46:39.0 |
HIP 40602 |
15.77 |
| 2026-05-23 12:00 |
08:18:50.60 |
+52:46:13.7 |
HIP 40602 |
16.26 |
| 2026-05-24 00:00 |
08:18:52.64 |
+52:45:48.5 |
HIP 40602 |
16.75 |
| 2026-05-24 12:00 |
08:18:54.71 |
+52:45:23.3 |
HIP 40602 |
17.25 |
| 2026-05-25 00:00 |
08:18:56.81 |
+52:44:58.2 |
HIP 40602 |
17.76 |
| 2026-05-25 12:00 |
08:18:58.93 |
+52:44:33.1 |
HIP 40602 |
18.27 |
| 2026-05-26 00:00 |
08:19:01.09 |
+52:44:08.1 |
HIP 40602 |
18.78 |
| 2026-05-26 12:00 |
08:19:03.27 |
+52:43:43.1 |
HIP 40602 |
19.30 |
| 2026-05-27 00:00 |
08:19:05.49 |
+52:43:18.1 |
HIP 40602 |
19.82 |
| 2026-05-27 12:00 |
08:19:07.73 |
+52:42:53.2 |
HIP 40602 |
20.34 |
| 2026-05-28 00:00 |
08:19:10.00 |
+52:42:28.4 |
HIP 40602 |
20.87 |
| 2026-05-28 12:00 |
08:19:12.30 |
+52:42:03.6 |
HIP 40602 |
21.40 |
| 2026-05-29 00:00 |
08:19:14.62 |
+52:41:38.9 |
HIP 40602 |
21.93 |
| 2026-05-29 12:00 |
08:19:16.98 |
+52:41:14.2 |
HIP 40602 |
22.47 |
| 2026-05-30 00:00 |
08:19:19.36 |
+52:40:49.6 |
HIP 40602 |
23.01 |
| 2026-05-30 12:00 |
08:19:21.77 |
+52:40:25.0 |
HIP 40602 |
23.55 |
| 2026-05-31 00:00 |
08:19:24.20 |
+52:40:00.5 |
HIP 40602 |
24.10 |
| 2026-05-31 12:00 |
08:19:26.66 |
+52:39:36.1 |
HIP 40602 |
24.65 |
| 2026-06-01 00:00 |
08:19:29.15 |
+52:39:11.7 |
HIP 40602 |
25.20 |
| 2026-06-01 12:00 |
08:19:31.67 |
+52:38:47.4 |
HIP 40602 |
25.75 |
| 2026-06-02 00:00 |
08:19:34.21 |
+52:38:23.2 |
HIP 40602 |
26.31 |