メタデータ
| 項目 |
値 |
| Designation |
C/2009 G1 (STEREO) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2009-04-16T12:08:09.119040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:30Z |
| Obs used |
119 |
| NEO |
- |
| M1 |
9.100 |
| K1 |
17.250 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2009-05-09.0000000 |
| e |
0.99767848 |
| q (au) |
1.128742 |
| a (au) |
486.208569 |
| i (deg) |
108.310256 |
| Ω (om, deg) |
120.634994 |
| ω (w, deg) |
175.444080 |
| M (ma, deg) |
0.002068 |
等級
散乱 + 全体線形
$$
M_a = (9.287 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
9.287 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.965 |
| 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 |
08:15:17.40 |
-03:56:57.0 |
HIP 40358 |
15.13 |
| 2026-05-12 12:00 |
08:15:18.44 |
-03:56:39.7 |
HIP 40358 |
15.22 |
| 2026-05-13 00:00 |
08:15:19.49 |
-03:56:22.5 |
HIP 40358 |
15.33 |
| 2026-05-13 12:00 |
08:15:20.57 |
-03:56:05.5 |
HIP 40358 |
15.46 |
| 2026-05-14 00:00 |
08:15:21.68 |
-03:55:48.5 |
HIP 40358 |
15.60 |
| 2026-05-14 12:00 |
08:15:22.81 |
-03:55:31.8 |
HIP 40358 |
15.76 |
| 2026-05-15 00:00 |
08:15:23.97 |
-03:55:15.2 |
HIP 40358 |
15.93 |
| 2026-05-15 12:00 |
08:15:25.15 |
-03:54:58.7 |
HIP 40358 |
16.11 |
| 2026-05-16 00:00 |
08:15:26.35 |
-03:54:42.4 |
HIP 40358 |
16.32 |
| 2026-05-16 12:00 |
08:15:27.58 |
-03:54:26.3 |
HIP 40358 |
16.53 |
| 2026-05-17 00:00 |
08:15:28.83 |
-03:54:10.3 |
HIP 40358 |
16.76 |
| 2026-05-17 12:00 |
08:15:30.11 |
-03:53:54.4 |
HIP 40358 |
17.00 |
| 2026-05-18 00:00 |
08:15:31.41 |
-03:53:38.7 |
HIP 40358 |
17.26 |
| 2026-05-18 12:00 |
08:15:32.74 |
-03:53:23.2 |
HIP 40358 |
17.52 |
| 2026-05-19 00:00 |
08:15:34.08 |
-03:53:07.8 |
HIP 40358 |
17.80 |
| 2026-05-19 12:00 |
08:15:35.46 |
-03:52:52.6 |
HIP 40358 |
18.09 |
| 2026-05-20 00:00 |
08:15:36.85 |
-03:52:37.5 |
HIP 40358 |
18.40 |
| 2026-05-20 12:00 |
08:15:38.27 |
-03:52:22.6 |
HIP 40358 |
18.71 |
| 2026-05-21 00:00 |
08:15:39.71 |
-03:52:07.9 |
HIP 40358 |
19.03 |
| 2026-05-21 12:00 |
08:15:41.18 |
-03:51:53.3 |
HIP 40358 |
19.37 |
| 2026-05-22 00:00 |
08:15:42.66 |
-03:51:38.9 |
HIP 40358 |
19.71 |
| 2026-05-22 12:00 |
08:15:44.17 |
-03:51:24.6 |
HIP 40358 |
20.07 |
| 2026-05-23 00:00 |
08:15:45.70 |
-03:51:10.5 |
HIP 40358 |
20.43 |
| 2026-05-23 12:00 |
08:15:47.26 |
-03:50:56.5 |
HIP 40358 |
20.81 |
| 2026-05-24 00:00 |
08:15:48.84 |
-03:50:42.8 |
HIP 40358 |
21.19 |
| 2026-05-24 12:00 |
08:15:50.44 |
-03:50:29.1 |
HIP 40358 |
21.58 |
| 2026-05-25 00:00 |
08:15:52.06 |
-03:50:15.7 |
HIP 40358 |
21.97 |
| 2026-05-25 12:00 |
08:15:53.70 |
-03:50:02.4 |
HIP 40358 |
22.38 |
| 2026-05-26 00:00 |
08:15:55.36 |
-03:49:49.3 |
HIP 40358 |
22.79 |
| 2026-05-26 12:00 |
08:15:57.05 |
-03:49:36.3 |
HIP 40358 |
23.22 |
| 2026-05-27 00:00 |
08:15:58.76 |
-03:49:23.5 |
HIP 40358 |
23.64 |
| 2026-05-27 12:00 |
08:16:00.48 |
-03:49:10.9 |
HIP 40358 |
24.08 |
| 2026-05-28 00:00 |
08:16:02.23 |
-03:48:58.4 |
HIP 40613 |
24.08 |
| 2026-05-28 12:00 |
08:16:04.00 |
-03:48:46.1 |
HIP 40613 |
23.77 |
| 2026-05-29 00:00 |
08:16:05.80 |
-03:48:34.0 |
HIP 40613 |
23.47 |
| 2026-05-29 12:00 |
08:16:07.61 |
-03:48:22.0 |
HIP 40613 |
23.16 |
| 2026-05-30 00:00 |
08:16:09.44 |
-03:48:10.2 |
HIP 40613 |
22.85 |
| 2026-05-30 12:00 |
08:16:11.29 |
-03:47:58.6 |
HIP 40613 |
22.55 |
| 2026-05-31 00:00 |
08:16:13.16 |
-03:47:47.1 |
HIP 40613 |
22.24 |
| 2026-05-31 12:00 |
08:16:15.06 |
-03:47:35.8 |
HIP 40613 |
21.94 |
| 2026-06-01 00:00 |
08:16:16.97 |
-03:47:24.7 |
HIP 40613 |
21.64 |
| 2026-06-01 12:00 |
08:16:18.90 |
-03:47:13.8 |
HIP 40613 |
21.34 |
| 2026-06-02 00:00 |
08:16:20.86 |
-03:47:03.0 |
HIP 40613 |
21.05 |