メタデータ
| 項目 |
値 |
| Designation |
P/2008 Y12 (SOHO) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2008-12-22T11:21:24.419520Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:27Z |
| Obs used |
76 |
| NEO |
Yes |
| M1 |
- |
| K1 |
- |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2010-10-24.0000000 |
| e |
0.97876170 |
| q (au) |
0.065376 |
| a (au) |
3.078198 |
| i (deg) |
23.345371 |
| Ω (om, deg) |
312.574737 |
| ω (w, deg) |
146.622073 |
| M (ma, deg) |
122.370129 |
等級
散乱 + 全体線形
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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) |
| 2026-07-29 00:00 |
17:59:05.40 |
-40:31:08.2 |
HIP 88098 |
13.64 |
| 2026-07-29 12:00 |
17:58:40.36 |
-40:29:44.4 |
HIP 87922 |
12.30 |
| 2026-07-30 00:00 |
17:58:15.59 |
-40:28:19.7 |
HIP 87922 |
8.69 |
| 2026-07-30 12:00 |
17:57:51.09 |
-40:26:54.2 |
HIP 87922 |
6.96 |
| 2026-07-31 00:00 |
17:57:26.86 |
-40:25:27.8 |
HIP 87848 |
7.79 |
| 2026-07-31 12:00 |
17:57:02.91 |
-40:24:00.7 |
HIP 87848 |
3.01 |
| 2026-08-01 00:00 |
17:56:39.24 |
-40:22:32.8 |
HIP 87848 |
1.73 |
| 2026-08-01 12:00 |
17:56:15.84 |
-40:21:04.1 |
HIP 87848 |
6.43 |
| 2026-08-02 00:00 |
17:55:52.72 |
-40:19:34.7 |
HIP 87848 |
11.08 |
| 2026-08-02 12:00 |
17:55:29.89 |
-40:18:04.6 |
HIP 87689 |
10.15 |
| 2026-08-03 00:00 |
17:55:07.33 |
-40:16:33.8 |
HIP 87688 |
5.64 |
| 2026-08-03 12:00 |
17:54:45.06 |
-40:15:02.3 |
HIP 87688 |
1.22 |
| 2026-08-04 00:00 |
17:54:23.07 |
-40:13:30.1 |
HIP 87688 |
3.42 |
| 2026-08-04 12:00 |
17:54:01.37 |
-40:11:57.4 |
HIP 87688 |
7.82 |
| 2026-08-05 00:00 |
17:53:39.96 |
-40:10:24.0 |
HIP 87688 |
12.19 |
| 2026-08-05 12:00 |
17:53:18.83 |
-40:08:50.0 |
HIP 87688 |
16.52 |
| 2026-08-06 00:00 |
17:52:57.99 |
-40:07:15.4 |
HIP 87688 |
20.80 |
| 2026-08-06 12:00 |
17:52:37.44 |
-40:05:40.3 |
HIP 87688 |
25.04 |
| 2026-08-07 00:00 |
17:52:17.18 |
-40:04:04.7 |
HIP 87330 |
24.12 |
| 2026-08-07 12:00 |
17:51:57.21 |
-40:02:28.5 |
HIP 87294 |
20.51 |
| 2026-08-08 00:00 |
17:51:37.54 |
-40:00:51.9 |
HIP 87294 |
17.16 |
| 2026-08-08 12:00 |
17:51:18.15 |
-39:59:14.8 |
HIP 87294 |
14.24 |
| 2026-08-09 00:00 |
17:50:59.07 |
-39:57:37.2 |
HIP 87294 |
12.05 |
| 2026-08-09 12:00 |
17:50:40.27 |
-39:55:59.2 |
HIP 87301 |
9.40 |
| 2026-08-10 00:00 |
17:50:21.77 |
-39:54:20.8 |
HIP 87301 |
6.75 |
| 2026-08-10 12:00 |
17:50:03.57 |
-39:52:41.9 |
HIP 87301 |
5.74 |
| 2026-08-11 00:00 |
17:49:45.66 |
-39:51:02.7 |
HIP 87301 |
7.03 |
| 2026-08-11 12:00 |
17:49:28.05 |
-39:49:23.2 |
HIP 87301 |
9.69 |
| 2026-08-12 00:00 |
17:49:10.74 |
-39:47:43.3 |
HIP 87181 |
8.21 |
| 2026-08-12 12:00 |
17:48:53.73 |
-39:46:03.0 |
HIP 87181 |
8.15 |
| 2026-08-13 00:00 |
17:48:37.01 |
-39:44:22.5 |
HIP 87181 |
9.62 |
| 2026-08-13 12:00 |
17:48:20.59 |
-39:42:41.7 |
HIP 87181 |
12.01 |
| 2026-08-14 00:00 |
17:48:04.47 |
-39:41:00.6 |
HIP 87181 |
14.86 |
| 2026-08-14 12:00 |
17:47:48.65 |
-39:39:19.3 |
HIP 87181 |
17.93 |
| 2026-08-15 00:00 |
17:47:33.13 |
-39:37:37.7 |
HIP 87198 |
19.20 |
| 2026-08-15 12:00 |
17:47:17.91 |
-39:35:55.9 |
HIP 87198 |
20.71 |
| 2026-08-16 00:00 |
17:47:02.98 |
-39:34:14.0 |
HIP 86983 |
19.37 |
| 2026-08-16 12:00 |
17:46:48.35 |
-39:32:31.8 |
HIP 86983 |
16.99 |
| 2026-08-17 00:00 |
17:46:34.02 |
-39:30:49.5 |
HIP 86983 |
14.95 |
| 2026-08-17 12:00 |
17:46:19.99 |
-39:29:07.0 |
HIP 86983 |
13.39 |
| 2026-08-18 00:00 |
17:46:06.25 |
-39:27:24.4 |
HIP 86983 |
12.45 |
| 2026-08-18 12:00 |
17:45:52.81 |
-39:25:41.7 |
HIP 86983 |
12.25 |
| 2026-08-19 00:00 |
17:45:39.67 |
-39:23:58.9 |
HIP 86983 |
12.77 |