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) |
| 2026-06-01 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 |
| 2026-06-02 12:00 |
15:24:27.28 |
-01:35:31.1 |
HIP 75500 |
14.61 |
| 2026-06-03 00:00 |
15:24:11.66 |
-01:36:03.7 |
HIP 75500 |
18.41 |
| 2026-06-03 12:00 |
15:23:56.14 |
-01:36:37.4 |
HIP 75262 |
19.42 |
| 2026-06-04 00:00 |
15:23:40.73 |
-01:37:12.4 |
HIP 75262 |
15.84 |
| 2026-06-04 12:00 |
15:23:25.41 |
-01:37:48.6 |
HIP 75262 |
12.48 |
| 2026-06-05 00:00 |
15:23:10.21 |
-01:38:26.0 |
HIP 75262 |
9.56 |
| 2026-06-05 12:00 |
15:22:55.11 |
-01:39:04.6 |
HIP 75262 |
7.56 |
| 2026-06-06 00:00 |
15:22:40.12 |
-01:39:44.5 |
HIP 75262 |
7.24 |
| 2026-06-06 12:00 |
15:22:25.25 |
-01:40:25.5 |
HIP 75262 |
8.77 |
| 2026-06-07 00:00 |
15:22:10.49 |
-01:41:07.7 |
HIP 75262 |
11.39 |
| 2026-06-07 12:00 |
15:21:55.85 |
-01:41:51.2 |
HIP 75262 |
14.51 |
| 2026-06-08 00:00 |
15:21:41.33 |
-01:42:35.8 |
HIP 75262 |
17.85 |
| 2026-06-08 12:00 |
15:21:26.93 |
-01:43:21.6 |
HIP 75262 |
21.29 |
| 2026-06-09 00:00 |
15:21:12.65 |
-01:44:08.7 |
HIP 75262 |
24.79 |
| 2026-06-09 12:00 |
15:20:58.50 |
-01:44:56.9 |
HIP 75261 |
28.29 |
| 2026-06-10 00:00 |
15:20:44.48 |
-01:45:46.4 |
HIP 74948 |
29.08 |
| 2026-06-10 12:00 |
15:20:30.59 |
-01:46:37.0 |
HIP 74948 |
26.20 |
| 2026-06-11 00:00 |
15:20:16.82 |
-01:47:28.8 |
HIP 74948 |
23.56 |
| 2026-06-11 12:00 |
15:20:03.19 |
-01:48:21.8 |
HIP 74948 |
21.21 |
| 2026-06-12 00:00 |
15:19:49.70 |
-01:49:16.0 |
HIP 74948 |
19.27 |
| 2026-06-12 12:00 |
15:19:36.35 |
-01:50:11.4 |
HIP 74948 |
17.84 |
| 2026-06-13 00:00 |
15:19:23.13 |
-01:51:08.0 |
HIP 74948 |
17.04 |
| 2026-06-13 12:00 |
15:19:10.06 |
-01:52:05.7 |
HIP 74948 |
16.94 |
| 2026-06-14 00:00 |
15:18:57.13 |
-01:53:04.7 |
HIP 74972 |
17.50 |
| 2026-06-14 12:00 |
15:18:44.34 |
-01:54:04.7 |
HIP 74972 |
17.65 |
| 2026-06-15 00:00 |
15:18:31.70 |
-01:55:06.0 |
HIP 74972 |
18.38 |
| 2026-06-15 12:00 |
15:18:19.21 |
-01:56:08.4 |
HIP 74972 |
19.61 |
| 2026-06-16 00:00 |
15:18:06.88 |
-01:57:12.0 |
HIP 74972 |
21.24 |
| 2026-06-16 12:00 |
15:17:54.69 |
-01:58:16.7 |
HIP 74889 |
23.08 |
| 2026-06-17 00:00 |
15:17:42.66 |
-01:59:22.6 |
HIP 74889 |
25.02 |
| 2026-06-17 12:00 |
15:17:30.78 |
-02:00:29.6 |
HIP 74889 |
27.20 |
| 2026-06-18 00:00 |
15:17:19.06 |
-02:01:37.8 |
HIP 74889 |
29.55 |
| 2026-06-18 12:00 |
15:17:07.50 |
-02:02:47.1 |
HIP 74889 |
32.04 |
| 2026-06-19 00:00 |
15:16:56.10 |
-02:03:57.5 |
HIP 74889 |
34.62 |
| 2026-06-19 12:00 |
15:16:44.86 |
-02:05:09.0 |
HIP 74633 |
33.26 |
| 2026-06-20 00:00 |
15:16:33.78 |
-02:06:21.6 |
HIP 74633 |
30.32 |
| 2026-06-20 12:00 |
15:16:22.87 |
-02:07:35.4 |
HIP 74633 |
27.42 |
| 2026-06-21 00:00 |
15:16:12.12 |
-02:08:50.2 |
HIP 74633 |
24.56 |
| 2026-06-21 12:00 |
15:16:01.54 |
-02:10:06.1 |
HIP 74633 |
21.74 |
| 2026-06-22 00:00 |
15:15:51.12 |
-02:11:23.1 |
HIP 74633 |
18.98 |