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) |
| 2026-03-26 00:00 |
08:15:40.06 |
-04:32:03.9 |
HIP 40323 |
26.28 |
| 2026-03-26 12:00 |
08:15:38.55 |
-04:31:38.6 |
HIP 40323 |
26.04 |
| 2026-03-27 00:00 |
08:15:37.07 |
-04:31:13.3 |
HIP 40323 |
25.81 |
| 2026-03-27 12:00 |
08:15:35.61 |
-04:30:48.0 |
HIP 40323 |
25.61 |
| 2026-03-28 00:00 |
08:15:34.18 |
-04:30:22.7 |
HIP 40323 |
25.42 |
| 2026-03-28 12:00 |
08:15:32.78 |
-04:29:57.5 |
HIP 40323 |
25.24 |
| 2026-03-29 00:00 |
08:15:31.40 |
-04:29:32.2 |
HIP 40323 |
25.08 |
| 2026-03-29 12:00 |
08:15:30.05 |
-04:29:07.0 |
HIP 40323 |
24.94 |
| 2026-03-30 00:00 |
08:15:28.73 |
-04:28:41.8 |
HIP 40323 |
24.82 |
| 2026-03-30 12:00 |
08:15:27.43 |
-04:28:16.7 |
HIP 40323 |
24.71 |
| 2026-03-31 00:00 |
08:15:26.16 |
-04:27:51.6 |
HIP 40323 |
24.62 |
| 2026-03-31 12:00 |
08:15:24.92 |
-04:27:26.5 |
HIP 40323 |
24.55 |
| 2026-04-01 00:00 |
08:15:23.70 |
-04:27:01.4 |
HIP 40323 |
24.49 |
| 2026-04-01 12:00 |
08:15:22.51 |
-04:26:36.4 |
HIP 40323 |
24.45 |
| 2026-04-02 00:00 |
08:15:21.35 |
-04:26:11.3 |
HIP 40323 |
24.42 |
| 2026-04-02 12:00 |
08:15:20.22 |
-04:25:46.4 |
HIP 40323 |
24.41 |
| 2026-04-03 00:00 |
08:15:19.11 |
-04:25:21.4 |
HIP 40323 |
24.42 |
| 2026-04-03 12:00 |
08:15:18.03 |
-04:24:56.5 |
HIP 40323 |
24.44 |
| 2026-04-04 00:00 |
08:15:16.97 |
-04:24:31.7 |
HIP 40323 |
24.47 |
| 2026-04-04 12:00 |
08:15:15.95 |
-04:24:06.9 |
HIP 40323 |
24.53 |
| 2026-04-05 00:00 |
08:15:14.95 |
-04:23:42.1 |
HIP 40323 |
24.59 |
| 2026-04-05 12:00 |
08:15:13.98 |
-04:23:17.4 |
HIP 40323 |
24.67 |
| 2026-04-06 00:00 |
08:15:13.03 |
-04:22:52.7 |
HIP 40323 |
24.76 |
| 2026-04-06 12:00 |
08:15:12.11 |
-04:22:28.1 |
HIP 40323 |
24.87 |
| 2026-04-07 00:00 |
08:15:11.22 |
-04:22:03.5 |
HIP 40323 |
24.99 |
| 2026-04-07 12:00 |
08:15:10.36 |
-04:21:38.9 |
HIP 40323 |
25.12 |
| 2026-04-08 00:00 |
08:15:09.53 |
-04:21:14.5 |
HIP 40323 |
25.26 |
| 2026-04-08 12:00 |
08:15:08.72 |
-04:20:50.0 |
HIP 40317 |
25.09 |
| 2026-04-09 00:00 |
08:15:07.94 |
-04:20:25.7 |
HIP 40317 |
24.66 |
| 2026-04-09 12:00 |
08:15:07.19 |
-04:20:01.3 |
HIP 40317 |
24.25 |
| 2026-04-10 00:00 |
08:15:06.47 |
-04:19:37.1 |
HIP 40317 |
23.84 |
| 2026-04-10 12:00 |
08:15:05.77 |
-04:19:12.9 |
HIP 40317 |
23.44 |
| 2026-04-11 00:00 |
08:15:05.10 |
-04:18:48.8 |
HIP 40317 |
23.04 |
| 2026-04-11 12:00 |
08:15:04.46 |
-04:18:24.7 |
HIP 40317 |
22.65 |
| 2026-04-12 00:00 |
08:15:03.85 |
-04:18:00.7 |
HIP 40317 |
22.27 |
| 2026-04-12 12:00 |
08:15:03.26 |
-04:17:36.8 |
HIP 40317 |
21.90 |
| 2026-04-13 00:00 |
08:15:02.71 |
-04:17:12.9 |
HIP 40317 |
21.53 |
| 2026-04-13 12:00 |
08:15:02.18 |
-04:16:49.1 |
HIP 40317 |
21.18 |
| 2026-04-14 00:00 |
08:15:01.68 |
-04:16:25.4 |
HIP 40317 |
20.83 |
| 2026-04-14 12:00 |
08:15:01.21 |
-04:16:01.7 |
HIP 40317 |
20.49 |
| 2026-04-15 00:00 |
08:15:00.76 |
-04:15:38.1 |
HIP 40317 |
20.16 |
| 2026-04-15 12:00 |
08:15:00.34 |
-04:15:14.7 |
HIP 40317 |
19.83 |
| 2026-04-16 00:00 |
08:14:59.95 |
-04:14:51.2 |
HIP 40317 |
19.52 |