メタデータ
| 項目 |
値 |
| Designation |
C/1989 A5 (Shoemaker) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1989-02-26T01:49:07.296960Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:38Z |
| Obs used |
77 |
| NEO |
- |
| M1 |
8.300 |
| K1 |
10.000 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1989-01-25.0000000 |
| e |
0.99551906 |
| q (au) |
2.639638 |
| a (au) |
589.081028 |
| i (deg) |
96.558535 |
| Ω (om, deg) |
137.139302 |
| ω (w, deg) |
19.104183 |
| M (ma, deg) |
359.997789 |
等級
散乱 + 全体線形
$$
M_a = (6.268 + 5.033\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
6.268 |
| n |
5.033 |
| gf |
1.000 |
| gb |
-0.872 |
| k |
1.000 |
| 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 |
21:18:43.97 |
-10:55:11.8 |
HIP 105139 |
13.34 |
| 2026-05-12 12:00 |
21:18:43.88 |
-10:55:11.0 |
HIP 105139 |
13.31 |
| 2026-05-13 00:00 |
21:18:43.76 |
-10:55:10.3 |
HIP 105139 |
13.28 |
| 2026-05-13 12:00 |
21:18:43.63 |
-10:55:09.7 |
HIP 105139 |
13.25 |
| 2026-05-14 00:00 |
21:18:43.49 |
-10:55:09.1 |
HIP 105139 |
13.21 |
| 2026-05-14 12:00 |
21:18:43.32 |
-10:55:08.7 |
HIP 105139 |
13.17 |
| 2026-05-15 00:00 |
21:18:43.15 |
-10:55:08.3 |
HIP 105139 |
13.13 |
| 2026-05-15 12:00 |
21:18:42.95 |
-10:55:07.9 |
HIP 105139 |
13.09 |
| 2026-05-16 00:00 |
21:18:42.74 |
-10:55:07.7 |
HIP 105139 |
13.04 |
| 2026-05-16 12:00 |
21:18:42.51 |
-10:55:07.5 |
HIP 105139 |
12.99 |
| 2026-05-17 00:00 |
21:18:42.27 |
-10:55:07.5 |
HIP 105139 |
12.93 |
| 2026-05-17 12:00 |
21:18:42.01 |
-10:55:07.4 |
HIP 105139 |
12.88 |
| 2026-05-18 00:00 |
21:18:41.73 |
-10:55:07.5 |
HIP 105139 |
12.82 |
| 2026-05-18 12:00 |
21:18:41.44 |
-10:55:07.7 |
HIP 105139 |
12.76 |
| 2026-05-19 00:00 |
21:18:41.13 |
-10:55:07.9 |
HIP 105139 |
12.69 |
| 2026-05-19 12:00 |
21:18:40.81 |
-10:55:08.2 |
HIP 105139 |
12.63 |
| 2026-05-20 00:00 |
21:18:40.47 |
-10:55:08.6 |
HIP 105139 |
12.56 |
| 2026-05-20 12:00 |
21:18:40.11 |
-10:55:09.1 |
HIP 105139 |
12.49 |
| 2026-05-21 00:00 |
21:18:39.74 |
-10:55:09.6 |
HIP 105139 |
12.41 |
| 2026-05-21 12:00 |
21:18:39.35 |
-10:55:10.2 |
HIP 105139 |
12.33 |
| 2026-05-22 00:00 |
21:18:38.94 |
-10:55:10.9 |
HIP 105139 |
12.25 |
| 2026-05-22 12:00 |
21:18:38.52 |
-10:55:11.7 |
HIP 105139 |
12.17 |
| 2026-05-23 00:00 |
21:18:38.08 |
-10:55:12.6 |
HIP 105139 |
12.09 |
| 2026-05-23 12:00 |
21:18:37.63 |
-10:55:13.5 |
HIP 105139 |
12.00 |
| 2026-05-24 00:00 |
21:18:37.16 |
-10:55:14.6 |
HIP 105139 |
11.91 |
| 2026-05-24 12:00 |
21:18:36.68 |
-10:55:15.7 |
HIP 105139 |
11.82 |
| 2026-05-25 00:00 |
21:18:36.18 |
-10:55:16.8 |
HIP 105139 |
11.73 |
| 2026-05-25 12:00 |
21:18:35.66 |
-10:55:18.1 |
HIP 105139 |
11.64 |
| 2026-05-26 00:00 |
21:18:35.13 |
-10:55:19.4 |
HIP 105139 |
11.54 |
| 2026-05-26 12:00 |
21:18:34.58 |
-10:55:20.8 |
HIP 105139 |
11.44 |
| 2026-05-27 00:00 |
21:18:34.02 |
-10:55:22.3 |
HIP 105139 |
11.34 |
| 2026-05-27 12:00 |
21:18:33.44 |
-10:55:23.9 |
HIP 105139 |
11.24 |
| 2026-05-28 00:00 |
21:18:32.85 |
-10:55:25.6 |
HIP 105139 |
11.14 |
| 2026-05-28 12:00 |
21:18:32.24 |
-10:55:27.3 |
HIP 105139 |
11.03 |
| 2026-05-29 00:00 |
21:18:31.62 |
-10:55:29.1 |
HIP 105139 |
10.93 |
| 2026-05-29 12:00 |
21:18:30.98 |
-10:55:31.0 |
HIP 105139 |
10.82 |
| 2026-05-30 00:00 |
21:18:30.32 |
-10:55:32.9 |
HIP 105139 |
10.72 |
| 2026-05-30 12:00 |
21:18:29.65 |
-10:55:35.0 |
HIP 105139 |
10.61 |
| 2026-05-31 00:00 |
21:18:28.97 |
-10:55:37.1 |
HIP 105139 |
10.50 |
| 2026-05-31 12:00 |
21:18:28.27 |
-10:55:39.3 |
HIP 105139 |
10.40 |
| 2026-06-01 00:00 |
21:18:27.55 |
-10:55:41.6 |
HIP 105139 |
10.29 |
| 2026-06-01 12:00 |
21:18:26.82 |
-10:55:43.9 |
HIP 105139 |
10.18 |
| 2026-06-02 00:00 |
21:18:26.08 |
-10:55:46.4 |
HIP 105139 |
10.07 |