メタデータ
| 項目 |
値 |
| Designation |
121P/Shoemaker-Holt 2 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2004-03-07T04:12:50.042880Z |
| Orbit solution date (soln_date, UTC) |
2025-06-26T10:13:18Z |
| Obs used |
769 |
| NEO |
- |
| M1 |
6.600 |
| K1 |
18.750 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2008-07-29.0000000 |
| e |
0.20653217 |
| q (au) |
3.578428 |
| a (au) |
4.509859 |
| i (deg) |
20.819382 |
| Ω (om, deg) |
96.006730 |
| ω (w, deg) |
18.114322 |
| M (ma, deg) |
165.153239 |
等級
散乱 + 全体線形
$$
M_a = (16.404 + 2.723\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
16.404 |
| n |
2.723 |
| gf |
1.000 |
| gb |
-0.696 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
15:36:38.07 |
-01:31:02.9 |
HIP 76246 |
32.40 |
| 2026-05-12 12:00 |
15:36:20.60 |
-01:30:45.0 |
HIP 76246 |
28.03 |
| 2026-05-13 00:00 |
15:36:03.12 |
-01:30:28.2 |
HIP 76246 |
23.66 |
| 2026-05-13 12:00 |
15:35:45.62 |
-01:30:12.5 |
HIP 76246 |
19.30 |
| 2026-05-14 00:00 |
15:35:28.10 |
-01:29:57.8 |
HIP 76246 |
14.95 |
| 2026-05-14 12:00 |
15:35:10.58 |
-01:29:44.2 |
HIP 76246 |
10.64 |
| 2026-05-15 00:00 |
15:34:53.05 |
-01:29:31.8 |
HIP 76246 |
6.41 |
| 2026-05-15 12:00 |
15:34:35.52 |
-01:29:20.4 |
HIP 76246 |
2.78 |
| 2026-05-16 00:00 |
15:34:17.98 |
-01:29:10.1 |
HIP 76246 |
3.58 |
| 2026-05-16 12:00 |
15:34:00.45 |
-01:29:01.0 |
HIP 76246 |
7.52 |
| 2026-05-17 00:00 |
15:33:42.93 |
-01:28:53.0 |
HIP 76246 |
11.77 |
| 2026-05-17 12:00 |
15:33:25.41 |
-01:28:46.1 |
HIP 76246 |
16.10 |
| 2026-05-18 00:00 |
15:33:07.91 |
-01:28:40.4 |
HIP 76133 |
17.67 |
| 2026-05-18 12:00 |
15:32:50.42 |
-01:28:35.8 |
HIP 76133 |
17.52 |
| 2026-05-19 00:00 |
15:32:32.95 |
-01:28:32.4 |
HIP 76133 |
18.45 |
| 2026-05-19 12:00 |
15:32:15.50 |
-01:28:30.1 |
HIP 76091 |
18.64 |
| 2026-05-20 00:00 |
15:31:58.08 |
-01:28:29.0 |
HIP 76091 |
19.65 |
| 2026-05-20 12:00 |
15:31:40.68 |
-01:28:29.1 |
HIP 75923 |
21.06 |
| 2026-05-21 00:00 |
15:31:23.32 |
-01:28:30.3 |
HIP 75923 |
17.29 |
| 2026-05-21 12:00 |
15:31:05.99 |
-01:28:32.8 |
HIP 75923 |
13.88 |
| 2026-05-22 00:00 |
15:30:48.69 |
-01:28:36.4 |
HIP 75923 |
11.15 |
| 2026-05-22 12:00 |
15:30:31.44 |
-01:28:41.2 |
HIP 75923 |
9.69 |
| 2026-05-23 00:00 |
15:30:14.23 |
-01:28:47.2 |
HIP 75923 |
10.04 |
| 2026-05-23 12:00 |
15:29:57.06 |
-01:28:54.4 |
HIP 75923 |
12.05 |
| 2026-05-24 00:00 |
15:29:39.94 |
-01:29:02.7 |
HIP 75923 |
15.05 |
| 2026-05-24 12:00 |
15:29:22.87 |
-01:29:12.3 |
HIP 75923 |
18.56 |
| 2026-05-25 00:00 |
15:29:05.86 |
-01:29:23.1 |
HIP 75923 |
22.33 |
| 2026-05-25 12:00 |
15:28:48.90 |
-01:29:35.1 |
HIP 75923 |
26.25 |
| 2026-05-26 00:00 |
15:28:32.00 |
-01:29:48.2 |
HIP 75648 |
27.18 |
| 2026-05-26 12:00 |
15:28:15.16 |
-01:30:02.6 |
HIP 75648 |
24.33 |
| 2026-05-27 00:00 |
15:27:58.39 |
-01:30:18.2 |
HIP 75648 |
21.92 |
| 2026-05-27 12:00 |
15:27:41.68 |
-01:30:35.0 |
HIP 75648 |
20.08 |
| 2026-05-28 00:00 |
15:27:25.04 |
-01:30:53.0 |
HIP 75648 |
18.99 |
| 2026-05-28 12:00 |
15:27:08.48 |
-01:31:12.2 |
HIP 75586 |
18.46 |
| 2026-05-29 00:00 |
15:26:51.98 |
-01:31:32.7 |
HIP 75586 |
17.12 |
| 2026-05-29 12:00 |
15:26:35.57 |
-01:31:54.3 |
HIP 75586 |
16.75 |
| 2026-05-30 00:00 |
15:26:19.23 |
-01:32:17.2 |
HIP 75500 |
15.06 |
| 2026-05-30 12:00 |
15:26:02.97 |
-01:32:41.2 |
HIP 75500 |
11.22 |
| 2026-05-31 00:00 |
15:25:46.80 |
-01:33:06.5 |
HIP 75500 |
7.67 |
| 2026-05-31 12:00 |
15:25:30.72 |
-01:33:33.0 |
HIP 75500 |
5.01 |
| 2026-06-01 00:00 |
15:25:14.72 |
-01:34:00.7 |
HIP 75500 |
4.92 |
| 2026-06-01 12:00 |
15:24:58.81 |
-01:34:29.6 |
HIP 75500 |
7.46 |
| 2026-06-02 00:00 |
15:24:43.00 |
-01:34:59.8 |
HIP 75500 |
10.90 |