C/2009 E1 (Itagaki)
メタデータ
| 項目 |
値 |
| Designation |
C/2009 E1 (Itagaki) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2009-04-07T22:05:17.583360Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:29Z |
| Obs used |
562 |
| NEO |
- |
| M1 |
13.500 |
| K1 |
16.500 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2009-04-29.0000000 |
| e |
0.98507270 |
| q (au) |
0.599722 |
| a (au) |
40.176157 |
| i (deg) |
127.453383 |
| Ω (om, deg) |
105.962011 |
| ω (w, deg) |
48.955232 |
| M (ma, deg) |
0.081586 |
等級
散乱 + 全体線形
$$
M_a = (15.401 + 5.839\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
15.401 |
| n |
5.839 |
| gf |
1.000 |
| gb |
-0.662 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2008-03-20 |
2009-03-20 |
-20.1936 |
-2.654 |
| 2009-03-20 |
2009-04-06 |
+19.3533 |
+2.016 |
| 2009-04-08 |
2009-04-27 |
-10.4953 |
-5.090 |
| 2009-04-27 |
2009-05-09 |
+2.4631 |
-2.572 |
| 2009-05-09 |
2009-05-29 |
-6.7742 |
-2.762 |
| 2009-05-29 |
2009-07-27 |
+9.1754 |
-2.409 |
| 2009-07-27 |
2009-08-19 |
-39.1092 |
+12.098 |
log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
17:19:44.14 |
-51:13:07.7 |
HIP 84753 |
7.43 |
| 2026-02-03 12:00 |
17:19:47.44 |
-51:13:31.3 |
HIP 84753 |
7.27 |
| 2026-02-04 00:00 |
17:19:50.70 |
-51:13:54.9 |
HIP 84753 |
7.17 |
| 2026-02-04 12:00 |
17:19:53.93 |
-51:14:18.7 |
HIP 84753 |
7.12 |
| 2026-02-05 00:00 |
17:19:57.11 |
-51:14:42.5 |
HIP 84753 |
7.12 |
| 2026-02-05 12:00 |
17:20:00.26 |
-51:15:06.5 |
HIP 84753 |
7.17 |
| 2026-02-06 00:00 |
17:20:03.37 |
-51:15:30.6 |
HIP 84753 |
7.27 |
| 2026-02-06 12:00 |
17:20:06.44 |
-51:15:54.7 |
HIP 84753 |
7.41 |
| 2026-02-07 00:00 |
17:20:09.47 |
-51:16:19.0 |
HIP 84753 |
7.60 |
| 2026-02-07 12:00 |
17:20:12.45 |
-51:16:43.4 |
HIP 84753 |
7.83 |
| 2026-02-08 00:00 |
17:20:15.40 |
-51:17:07.9 |
HIP 84753 |
8.09 |
| 2026-02-08 12:00 |
17:20:18.31 |
-51:17:32.4 |
HIP 84753 |
8.38 |
| 2026-02-09 00:00 |
17:20:21.18 |
-51:17:57.1 |
HIP 84753 |
8.70 |
| 2026-02-09 12:00 |
17:20:24.00 |
-51:18:21.9 |
HIP 84753 |
9.04 |
| 2026-02-10 00:00 |
17:20:26.79 |
-51:18:46.7 |
HIP 84753 |
9.40 |
| 2026-02-10 12:00 |
17:20:29.53 |
-51:19:11.7 |
HIP 84753 |
9.78 |
| 2026-02-11 00:00 |
17:20:32.23 |
-51:19:36.7 |
HIP 84753 |
10.17 |
| 2026-02-11 12:00 |
17:20:34.89 |
-51:20:01.8 |
HIP 84753 |
10.58 |
| 2026-02-12 00:00 |
17:20:37.50 |
-51:20:27.0 |
HIP 84753 |
10.99 |
| 2026-02-12 12:00 |
17:20:40.08 |
-51:20:52.3 |
HIP 84753 |
11.42 |
| 2026-02-13 00:00 |
17:20:42.61 |
-51:21:17.7 |
HIP 84753 |
11.85 |
| 2026-02-13 12:00 |
17:20:45.09 |
-51:21:43.1 |
HIP 84753 |
12.28 |
| 2026-02-14 00:00 |
17:20:47.54 |
-51:22:08.7 |
HIP 84753 |
12.72 |
| 2026-02-14 12:00 |
17:20:49.94 |
-51:22:34.3 |
HIP 84753 |
13.16 |
| 2026-02-15 00:00 |
17:20:52.29 |
-51:23:00.0 |
HIP 84753 |
13.61 |
| 2026-02-15 12:00 |
17:20:54.60 |
-51:23:25.8 |
HIP 84753 |
14.06 |
| 2026-02-16 00:00 |
17:20:56.87 |
-51:23:51.6 |
HIP 84753 |
14.51 |
| 2026-02-16 12:00 |
17:20:59.09 |
-51:24:17.5 |
HIP 84753 |
14.96 |
| 2026-02-17 00:00 |
17:21:01.27 |
-51:24:43.5 |
HIP 84753 |
15.41 |
| 2026-02-17 12:00 |
17:21:03.40 |
-51:25:09.5 |
HIP 84753 |
15.86 |
| 2026-02-18 00:00 |
17:21:05.49 |
-51:25:35.7 |
HIP 84753 |
16.31 |
| 2026-02-18 12:00 |
17:21:07.53 |
-51:26:01.8 |
HIP 84753 |
16.76 |
| 2026-02-19 00:00 |
17:21:09.53 |
-51:26:28.1 |
HIP 84753 |
17.21 |
| 2026-02-19 12:00 |
17:21:11.48 |
-51:26:54.4 |
HIP 84753 |
17.65 |
| 2026-02-20 00:00 |
17:21:13.38 |
-51:27:20.7 |
HIP 84753 |
18.10 |
| 2026-02-20 12:00 |
17:21:15.24 |
-51:27:47.2 |
HIP 84753 |
18.54 |
| 2026-02-21 00:00 |
17:21:17.05 |
-51:28:13.6 |
HIP 84753 |
18.98 |
| 2026-02-21 12:00 |
17:21:18.81 |
-51:28:40.2 |
HIP 84753 |
19.42 |
| 2026-02-22 00:00 |
17:21:20.53 |
-51:29:06.8 |
HIP 84753 |
19.86 |
| 2026-02-22 12:00 |
17:21:22.20 |
-51:29:33.4 |
HIP 84753 |
20.29 |
| 2026-02-23 00:00 |
17:21:23.83 |
-51:30:00.1 |
HIP 84753 |
20.73 |
| 2026-02-23 12:00 |
17:21:25.40 |
-51:30:26.8 |
HIP 84753 |
21.16 |
| 2026-02-24 00:00 |
17:21:26.93 |
-51:30:53.6 |
HIP 84967 |
20.73 |