メタデータ
| 項目 |
値 |
| Designation |
121P/Shoemaker-Holt 2 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2004-02-28T21:35:48.249600Z |
| Orbit solution date (soln_date, UTC) |
2026-05-22T14:12:30Z |
| Obs used |
772 |
| NEO |
- |
| M1 |
6.700 |
| K1 |
18.500 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2008-08-22.0000000 |
| e |
0.20402943 |
| q (au) |
3.596644 |
| a (au) |
4.518564 |
| i (deg) |
20.725153 |
| Ω (om, deg) |
95.964916 |
| ω (w, deg) |
18.015655 |
| M (ma, deg) |
167.885521 |
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) |
| 2026-09-25 00:00 |
15:35:26.52 |
-09:17:19.7 |
HIP 76243 |
16.10 |
| 2026-09-25 12:00 |
15:35:46.49 |
-09:19:49.7 |
HIP 76243 |
21.61 |
| 2026-09-26 00:00 |
15:36:06.56 |
-09:22:19.6 |
HIP 76243 |
27.16 |
| 2026-09-26 12:00 |
15:36:26.73 |
-09:24:49.3 |
HIP 76517 |
28.26 |
| 2026-09-27 00:00 |
15:36:47.00 |
-09:27:18.8 |
HIP 76570 |
23.16 |
| 2026-09-27 12:00 |
15:37:07.36 |
-09:29:48.1 |
HIP 76570 |
17.64 |
| 2026-09-28 00:00 |
15:37:27.82 |
-09:32:17.2 |
HIP 76570 |
12.16 |
| 2026-09-28 12:00 |
15:37:48.37 |
-09:34:46.0 |
HIP 76570 |
6.90 |
| 2026-09-29 00:00 |
15:38:09.02 |
-09:37:14.7 |
HIP 76570 |
3.32 |
| 2026-09-29 12:00 |
15:38:29.77 |
-09:39:43.1 |
HIP 76570 |
6.22 |
| 2026-09-30 00:00 |
15:38:50.60 |
-09:42:11.3 |
HIP 76570 |
11.45 |
| 2026-09-30 12:00 |
15:39:11.54 |
-09:44:39.3 |
HIP 76682 |
10.76 |
| 2026-10-01 00:00 |
15:39:32.56 |
-09:47:07.1 |
HIP 76703 |
10.34 |
| 2026-10-01 12:00 |
15:39:53.68 |
-09:49:34.6 |
HIP 76703 |
12.65 |
| 2026-10-02 00:00 |
15:40:14.89 |
-09:52:01.9 |
HIP 76703 |
16.73 |
| 2026-10-02 12:00 |
15:40:36.18 |
-09:54:29.0 |
HIP 76703 |
21.60 |
| 2026-10-03 00:00 |
15:40:57.57 |
-09:56:55.8 |
HIP 76703 |
26.85 |
| 2026-10-03 12:00 |
15:41:19.05 |
-09:59:22.3 |
HIP 76703 |
32.31 |
| 2026-10-04 00:00 |
15:41:40.62 |
-10:01:48.6 |
HIP 77019 |
28.17 |
| 2026-10-04 12:00 |
15:42:02.28 |
-10:04:14.7 |
HIP 77019 |
22.50 |
| 2026-10-05 00:00 |
15:42:24.02 |
-10:06:40.5 |
HIP 77019 |
16.94 |
| 2026-10-05 12:00 |
15:42:45.85 |
-10:09:06.1 |
HIP 77019 |
11.67 |
| 2026-10-06 00:00 |
15:43:07.77 |
-10:11:31.3 |
HIP 77019 |
7.39 |
| 2026-10-06 12:00 |
15:43:29.78 |
-10:13:56.3 |
HIP 77019 |
6.56 |
| 2026-10-07 00:00 |
15:43:51.87 |
-10:16:21.1 |
HIP 77019 |
10.09 |
| 2026-10-07 12:00 |
15:44:14.04 |
-10:18:45.5 |
HIP 77019 |
15.22 |
| 2026-10-08 00:00 |
15:44:36.30 |
-10:21:09.7 |
HIP 77019 |
20.81 |
| 2026-10-08 12:00 |
15:44:58.64 |
-10:23:33.6 |
HIP 77019 |
26.58 |
| 2026-10-09 00:00 |
15:45:21.06 |
-10:25:57.2 |
HIP 77274 |
25.92 |
| 2026-10-09 12:00 |
15:45:43.57 |
-10:28:20.5 |
HIP 77274 |
24.25 |
| 2026-10-10 00:00 |
15:46:06.15 |
-10:30:43.5 |
HIP 77342 |
22.80 |
| 2026-10-10 12:00 |
15:46:28.82 |
-10:33:06.2 |
HIP 77342 |
20.23 |
| 2026-10-11 00:00 |
15:46:51.56 |
-10:35:28.6 |
HIP 77342 |
19.29 |
| 2026-10-11 12:00 |
15:47:14.38 |
-10:37:50.7 |
HIP 77349 |
16.10 |
| 2026-10-12 00:00 |
15:47:37.28 |
-10:40:12.4 |
HIP 77349 |
13.87 |
| 2026-10-12 12:00 |
15:48:00.26 |
-10:42:33.9 |
HIP 77349 |
14.16 |
| 2026-10-13 00:00 |
15:48:23.31 |
-10:44:55.0 |
HIP 77349 |
16.85 |
| 2026-10-13 12:00 |
15:48:46.44 |
-10:47:15.8 |
HIP 77349 |
21.06 |
| 2026-10-14 00:00 |
15:49:09.65 |
-10:49:36.3 |
HIP 77546 |
18.78 |
| 2026-10-14 12:00 |
15:49:32.92 |
-10:51:56.4 |
HIP 77546 |
13.52 |
| 2026-10-15 00:00 |
15:49:56.27 |
-10:54:16.2 |
HIP 77546 |
9.44 |
| 2026-10-15 12:00 |
15:50:19.69 |
-10:56:35.7 |
HIP 77546 |
8.51 |
| 2026-10-16 00:00 |
15:50:43.18 |
-10:58:54.8 |
HIP 77546 |
11.52 |