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
$$
M_a = (15.399 + 5.843\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
15.399 |
| n |
5.843 |
| gf |
0.999 |
| 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 |
-20.1855 |
-2.656 |
| 2009-03-20 |
2009-04-06 |
+18.5279 |
+1.854 |
| 2009-04-08 |
2009-05-09 |
+5.8500 |
-2.134 |
| 2009-05-09 |
2009-05-27 |
-15.6182 |
-2.738 |
| 2009-05-27 |
2009-06-21 |
+20.5841 |
-3.922 |
| 2009-06-21 |
2009-07-04 |
+33.7456 |
-7.368 |
| 2009-07-04 |
2009-08-19 |
-24.8681 |
+6.863 |
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) |
| 2026-09-25 00:00 |
16:59:07.64 |
-51:24:24.2 |
HIP 83133 |
14.71 |
| 2026-09-25 12:00 |
16:59:09.13 |
-51:24:02.6 |
HIP 83133 |
14.32 |
| 2026-09-26 00:00 |
16:59:10.67 |
-51:23:41.1 |
HIP 83133 |
13.94 |
| 2026-09-26 12:00 |
16:59:12.26 |
-51:23:19.7 |
HIP 83133 |
13.56 |
| 2026-09-27 00:00 |
16:59:13.89 |
-51:22:58.4 |
HIP 83133 |
13.18 |
| 2026-09-27 12:00 |
16:59:15.56 |
-51:22:37.2 |
HIP 83133 |
12.81 |
| 2026-09-28 00:00 |
16:59:17.28 |
-51:22:16.1 |
HIP 83133 |
12.45 |
| 2026-09-28 12:00 |
16:59:19.04 |
-51:21:55.2 |
HIP 83133 |
12.09 |
| 2026-09-29 00:00 |
16:59:20.84 |
-51:21:34.3 |
HIP 83133 |
11.75 |
| 2026-09-29 12:00 |
16:59:22.69 |
-51:21:13.6 |
HIP 83133 |
11.41 |
| 2026-09-30 00:00 |
16:59:24.58 |
-51:20:53.0 |
HIP 83133 |
11.08 |
| 2026-09-30 12:00 |
16:59:26.51 |
-51:20:32.5 |
HIP 83133 |
10.76 |
| 2026-10-01 00:00 |
16:59:28.49 |
-51:20:12.2 |
HIP 83133 |
10.46 |
| 2026-10-01 12:00 |
16:59:30.51 |
-51:19:51.9 |
HIP 83133 |
10.17 |
| 2026-10-02 00:00 |
16:59:32.57 |
-51:19:31.8 |
HIP 83133 |
9.90 |
| 2026-10-02 12:00 |
16:59:34.68 |
-51:19:11.8 |
HIP 83226 |
9.55 |
| 2026-10-03 00:00 |
16:59:36.83 |
-51:18:52.0 |
HIP 83226 |
9.11 |
| 2026-10-03 12:00 |
16:59:39.02 |
-51:18:32.3 |
HIP 83226 |
8.66 |
| 2026-10-04 00:00 |
16:59:41.25 |
-51:18:12.7 |
HIP 83226 |
8.22 |
| 2026-10-04 12:00 |
16:59:43.52 |
-51:17:53.2 |
HIP 83226 |
7.77 |
| 2026-10-05 00:00 |
16:59:45.84 |
-51:17:33.9 |
HIP 83226 |
7.33 |
| 2026-10-05 12:00 |
16:59:48.20 |
-51:17:14.7 |
HIP 83226 |
6.88 |
| 2026-10-06 00:00 |
16:59:50.60 |
-51:16:55.7 |
HIP 83226 |
6.43 |
| 2026-10-06 12:00 |
16:59:53.04 |
-51:16:36.7 |
HIP 83226 |
5.98 |
| 2026-10-07 00:00 |
16:59:55.52 |
-51:16:18.0 |
HIP 83226 |
5.54 |
| 2026-10-07 12:00 |
16:59:58.04 |
-51:15:59.3 |
HIP 83226 |
5.10 |
| 2026-10-08 00:00 |
17:00:00.61 |
-51:15:40.8 |
HIP 83226 |
4.67 |
| 2026-10-08 12:00 |
17:00:03.21 |
-51:15:22.5 |
HIP 83226 |
4.24 |
| 2026-10-09 00:00 |
17:00:05.86 |
-51:15:04.3 |
HIP 83226 |
3.83 |
| 2026-10-09 12:00 |
17:00:08.54 |
-51:14:46.2 |
HIP 83226 |
3.44 |
| 2026-10-10 00:00 |
17:00:11.27 |
-51:14:28.3 |
HIP 83226 |
3.09 |
| 2026-10-10 12:00 |
17:00:14.03 |
-51:14:10.6 |
HIP 83226 |
2.77 |
| 2026-10-11 00:00 |
17:00:16.83 |
-51:13:52.9 |
HIP 83226 |
2.53 |
| 2026-10-11 12:00 |
17:00:19.68 |
-51:13:35.5 |
HIP 83226 |
2.37 |
| 2026-10-12 00:00 |
17:00:22.56 |
-51:13:18.2 |
HIP 83226 |
2.31 |
| 2026-10-12 12:00 |
17:00:25.48 |
-51:13:01.0 |
HIP 83226 |
2.38 |
| 2026-10-13 00:00 |
17:00:28.44 |
-51:12:44.0 |
HIP 83226 |
2.55 |
| 2026-10-13 12:00 |
17:00:31.43 |
-51:12:27.2 |
HIP 83226 |
2.82 |
| 2026-10-14 00:00 |
17:00:34.47 |
-51:12:10.5 |
HIP 83226 |
3.16 |
| 2026-10-14 12:00 |
17:00:37.54 |
-51:11:53.9 |
HIP 83226 |
3.56 |
| 2026-10-15 00:00 |
17:00:40.65 |
-51:11:37.6 |
HIP 83226 |
3.99 |
| 2026-10-15 12:00 |
17:00:43.79 |
-51:11:21.3 |
HIP 83226 |
4.45 |
| 2026-10-16 00:00 |
17:00:46.98 |
-51:11:05.3 |
HIP 83226 |
4.93 |