121P/Shoemaker-Holt 2
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) |
| 2026-02-03 00:00 |
15:46:52.51 |
-03:57:30.3 |
HIP 77266 |
8.15 |
| 2026-02-03 12:00 |
15:47:07.53 |
-03:57:27.5 |
HIP 77279 |
10.54 |
| 2026-02-04 00:00 |
15:47:22.40 |
-03:57:23.8 |
HIP 77279 |
13.17 |
| 2026-02-04 12:00 |
15:47:37.10 |
-03:57:19.3 |
HIP 77279 |
16.19 |
| 2026-02-05 00:00 |
15:47:51.65 |
-03:57:13.8 |
HIP 77464 |
18.17 |
| 2026-02-05 12:00 |
15:48:06.04 |
-03:57:07.5 |
HIP 77464 |
14.99 |
| 2026-02-06 00:00 |
15:48:20.26 |
-03:57:00.3 |
HIP 77464 |
12.06 |
| 2026-02-06 12:00 |
15:48:34.33 |
-03:56:52.3 |
HIP 77464 |
9.57 |
| 2026-02-07 00:00 |
15:48:48.22 |
-03:56:43.3 |
HIP 77464 |
7.91 |
| 2026-02-07 12:00 |
15:49:01.96 |
-03:56:33.5 |
HIP 77464 |
7.56 |
| 2026-02-08 00:00 |
15:49:15.52 |
-03:56:22.8 |
HIP 77464 |
8.64 |
| 2026-02-08 12:00 |
15:49:28.92 |
-03:56:11.3 |
HIP 77542 |
7.25 |
| 2026-02-09 00:00 |
15:49:42.16 |
-03:55:58.9 |
HIP 77542 |
3.96 |
| 2026-02-09 12:00 |
15:49:55.22 |
-03:55:45.6 |
HIP 77542 |
0.80 |
| 2026-02-10 00:00 |
15:50:08.11 |
-03:55:31.5 |
HIP 77542 |
2.59 |
| 2026-02-10 12:00 |
15:50:20.83 |
-03:55:16.5 |
HIP 77542 |
5.75 |
| 2026-02-11 00:00 |
15:50:33.38 |
-03:55:00.7 |
HIP 77542 |
8.89 |
| 2026-02-11 12:00 |
15:50:45.76 |
-03:54:44.0 |
HIP 77542 |
11.98 |
| 2026-02-12 00:00 |
15:50:57.96 |
-03:54:26.5 |
HIP 77542 |
15.04 |
| 2026-02-12 12:00 |
15:51:09.98 |
-03:54:08.1 |
HIP 77542 |
18.05 |
| 2026-02-13 00:00 |
15:51:21.83 |
-03:53:49.0 |
HIP 77542 |
21.02 |
| 2026-02-13 12:00 |
15:51:33.50 |
-03:53:28.9 |
HIP 77542 |
23.95 |
| 2026-02-14 00:00 |
15:51:44.99 |
-03:53:08.1 |
HIP 77542 |
26.83 |
| 2026-02-14 12:00 |
15:51:56.30 |
-03:52:46.5 |
HIP 77542 |
29.67 |
| 2026-02-15 00:00 |
15:52:07.44 |
-03:52:24.0 |
HIP 77542 |
32.47 |
| 2026-02-15 12:00 |
15:52:18.39 |
-03:52:00.7 |
HIP 77542 |
35.23 |
| 2026-02-16 00:00 |
15:52:29.15 |
-03:51:36.6 |
HIP 77542 |
37.94 |
| 2026-02-16 12:00 |
15:52:39.74 |
-03:51:11.8 |
HIP 77899 |
37.44 |
| 2026-02-17 00:00 |
15:52:50.14 |
-03:50:46.1 |
HIP 77899 |
35.91 |
| 2026-02-17 12:00 |
15:53:00.35 |
-03:50:19.6 |
HIP 77899 |
34.54 |
| 2026-02-18 00:00 |
15:53:10.38 |
-03:49:52.4 |
HIP 77899 |
33.36 |
| 2026-02-18 12:00 |
15:53:20.22 |
-03:49:24.4 |
HIP 77899 |
32.37 |
| 2026-02-19 00:00 |
15:53:29.87 |
-03:48:55.6 |
HIP 77899 |
31.58 |
| 2026-02-19 12:00 |
15:53:39.34 |
-03:48:26.0 |
HIP 77899 |
30.99 |
| 2026-02-20 00:00 |
15:53:48.61 |
-03:47:55.7 |
HIP 77899 |
30.61 |
| 2026-02-20 12:00 |
15:53:57.70 |
-03:47:24.6 |
HIP 77899 |
30.44 |
| 2026-02-21 00:00 |
15:54:06.59 |
-03:46:52.8 |
HIP 77899 |
30.46 |
| 2026-02-21 12:00 |
15:54:15.29 |
-03:46:20.3 |
HIP 77899 |
30.68 |
| 2026-02-22 00:00 |
15:54:23.80 |
-03:45:47.0 |
HIP 77899 |
31.06 |
| 2026-02-22 12:00 |
15:54:32.12 |
-03:45:13.0 |
HIP 77899 |
31.61 |
| 2026-02-23 00:00 |
15:54:40.24 |
-03:44:38.2 |
HIP 77899 |
32.30 |
| 2026-02-23 12:00 |
15:54:48.16 |
-03:44:02.8 |
HIP 77899 |
33.11 |
| 2026-02-24 00:00 |
15:54:55.90 |
-03:43:26.7 |
HIP 77899 |
34.03 |