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) |
| 2026-06-01 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 |
| 2026-06-02 12:00 |
08:19:36.78 |
+52:37:59.0 |
HIP 40602 |
26.87 |
| 2026-06-03 00:00 |
08:19:39.37 |
+52:37:34.9 |
HIP 40602 |
27.43 |
| 2026-06-03 12:00 |
08:19:41.99 |
+52:37:10.8 |
HIP 40602 |
27.99 |
| 2026-06-04 00:00 |
08:19:44.63 |
+52:36:46.9 |
HIP 41069 |
27.77 |
| 2026-06-04 12:00 |
08:19:47.30 |
+52:36:23.0 |
HIP 41069 |
27.38 |
| 2026-06-05 00:00 |
08:19:50.00 |
+52:35:59.1 |
HIP 41069 |
27.00 |
| 2026-06-05 12:00 |
08:19:52.72 |
+52:35:35.4 |
HIP 41069 |
26.62 |
| 2026-06-06 00:00 |
08:19:55.46 |
+52:35:11.7 |
HIP 41069 |
26.24 |
| 2026-06-06 12:00 |
08:19:58.23 |
+52:34:48.1 |
HIP 41069 |
25.86 |
| 2026-06-07 00:00 |
08:20:01.03 |
+52:34:24.6 |
HIP 41069 |
25.49 |
| 2026-06-07 12:00 |
08:20:03.84 |
+52:34:01.1 |
HIP 41069 |
25.12 |
| 2026-06-08 00:00 |
08:20:06.69 |
+52:33:37.7 |
HIP 41069 |
24.75 |
| 2026-06-08 12:00 |
08:20:09.55 |
+52:33:14.5 |
HIP 41069 |
24.39 |
| 2026-06-09 00:00 |
08:20:12.44 |
+52:32:51.2 |
HIP 41069 |
24.03 |
| 2026-06-09 12:00 |
08:20:15.36 |
+52:32:28.1 |
HIP 41069 |
23.68 |
| 2026-06-10 00:00 |
08:20:18.29 |
+52:32:05.1 |
HIP 41069 |
23.34 |
| 2026-06-10 12:00 |
08:20:21.25 |
+52:31:42.1 |
HIP 41069 |
23.00 |
| 2026-06-11 00:00 |
08:20:24.23 |
+52:31:19.3 |
HIP 41069 |
22.67 |
| 2026-06-11 12:00 |
08:20:27.24 |
+52:30:56.5 |
HIP 41069 |
22.34 |
| 2026-06-12 00:00 |
08:20:30.27 |
+52:30:33.8 |
HIP 41069 |
22.02 |
| 2026-06-12 12:00 |
08:20:33.31 |
+52:30:11.2 |
HIP 41069 |
21.71 |
| 2026-06-13 00:00 |
08:20:36.39 |
+52:29:48.7 |
HIP 41069 |
21.41 |
| 2026-06-13 12:00 |
08:20:39.48 |
+52:29:26.3 |
HIP 41069 |
21.12 |
| 2026-06-14 00:00 |
08:20:42.59 |
+52:29:04.0 |
HIP 41069 |
20.83 |
| 2026-06-14 12:00 |
08:20:45.73 |
+52:28:41.7 |
HIP 41069 |
20.56 |
| 2026-06-15 00:00 |
08:20:48.88 |
+52:28:19.6 |
HIP 41069 |
20.29 |
| 2026-06-15 12:00 |
08:20:52.06 |
+52:27:57.6 |
HIP 41069 |
20.04 |
| 2026-06-16 00:00 |
08:20:55.26 |
+52:27:35.7 |
HIP 41069 |
19.80 |
| 2026-06-16 12:00 |
08:20:58.48 |
+52:27:13.8 |
HIP 41069 |
19.57 |
| 2026-06-17 00:00 |
08:21:01.72 |
+52:26:52.1 |
HIP 41069 |
19.36 |
| 2026-06-17 12:00 |
08:21:04.97 |
+52:26:30.5 |
HIP 41069 |
19.15 |
| 2026-06-18 00:00 |
08:21:08.25 |
+52:26:09.0 |
HIP 41069 |
18.97 |
| 2026-06-18 12:00 |
08:21:11.55 |
+52:25:47.6 |
HIP 41069 |
18.79 |
| 2026-06-19 00:00 |
08:21:14.86 |
+52:25:26.3 |
HIP 41069 |
18.64 |
| 2026-06-19 12:00 |
08:21:18.20 |
+52:25:05.1 |
HIP 41069 |
18.49 |
| 2026-06-20 00:00 |
08:21:21.55 |
+52:24:44.0 |
HIP 41069 |
18.37 |
| 2026-06-20 12:00 |
08:21:24.92 |
+52:24:23.0 |
HIP 41069 |
18.26 |
| 2026-06-21 00:00 |
08:21:28.31 |
+52:24:02.2 |
HIP 41069 |
18.17 |
| 2026-06-21 12:00 |
08:21:31.72 |
+52:23:41.4 |
HIP 41069 |
18.09 |
| 2026-06-22 00:00 |
08:21:35.14 |
+52:23:20.8 |
HIP 41069 |
18.04 |