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) |
| 2026-09-20 00:00 |
21:12:33.44 |
-11:25:37.4 |
HIP 104654 |
10.21 |
| 2026-09-20 12:00 |
21:12:32.02 |
-11:25:46.7 |
HIP 104654 |
9.84 |
| 2026-09-21 00:00 |
21:12:30.61 |
-11:25:56.0 |
HIP 104654 |
9.46 |
| 2026-09-21 12:00 |
21:12:29.21 |
-11:26:05.2 |
HIP 104654 |
9.09 |
| 2026-09-22 00:00 |
21:12:27.82 |
-11:26:14.4 |
HIP 104654 |
8.72 |
| 2026-09-22 12:00 |
21:12:26.45 |
-11:26:23.6 |
HIP 104654 |
8.35 |
| 2026-09-23 00:00 |
21:12:25.08 |
-11:26:32.7 |
HIP 104654 |
7.98 |
| 2026-09-23 12:00 |
21:12:23.73 |
-11:26:41.8 |
HIP 104654 |
7.62 |
| 2026-09-24 00:00 |
21:12:22.39 |
-11:26:50.8 |
HIP 104654 |
7.26 |
| 2026-09-24 12:00 |
21:12:21.06 |
-11:26:59.8 |
HIP 104654 |
6.91 |
| 2026-09-25 00:00 |
21:12:19.75 |
-11:27:08.8 |
HIP 104654 |
6.56 |
| 2026-09-25 12:00 |
21:12:18.45 |
-11:27:17.7 |
HIP 104654 |
6.21 |
| 2026-09-26 00:00 |
21:12:17.15 |
-11:27:26.6 |
HIP 104654 |
5.86 |
| 2026-09-26 12:00 |
21:12:15.88 |
-11:27:35.4 |
HIP 104654 |
5.52 |
| 2026-09-27 00:00 |
21:12:14.61 |
-11:27:44.2 |
HIP 104654 |
5.18 |
| 2026-09-27 12:00 |
21:12:13.36 |
-11:27:52.9 |
HIP 104654 |
4.85 |
| 2026-09-28 00:00 |
21:12:12.11 |
-11:28:01.6 |
HIP 104654 |
4.52 |
| 2026-09-28 12:00 |
21:12:10.89 |
-11:28:10.3 |
HIP 104654 |
4.19 |
| 2026-09-29 00:00 |
21:12:09.67 |
-11:28:18.9 |
HIP 104654 |
3.87 |
| 2026-09-29 12:00 |
21:12:08.47 |
-11:28:27.4 |
HIP 104654 |
3.55 |
| 2026-09-30 00:00 |
21:12:07.28 |
-11:28:36.0 |
HIP 104654 |
3.24 |
| 2026-09-30 12:00 |
21:12:06.10 |
-11:28:44.4 |
HIP 104654 |
2.93 |
| 2026-10-01 00:00 |
21:12:04.94 |
-11:28:52.8 |
HIP 104654 |
2.62 |
| 2026-10-01 12:00 |
21:12:03.79 |
-11:29:01.2 |
HIP 104654 |
2.33 |
| 2026-10-02 00:00 |
21:12:02.66 |
-11:29:09.5 |
HIP 104654 |
2.04 |
| 2026-10-02 12:00 |
21:12:01.53 |
-11:29:17.8 |
HIP 104654 |
1.76 |
| 2026-10-03 00:00 |
21:12:00.43 |
-11:29:26.0 |
HIP 104654 |
1.50 |
| 2026-10-03 12:00 |
21:11:59.33 |
-11:29:34.2 |
HIP 104654 |
1.25 |
| 2026-10-04 00:00 |
21:11:58.25 |
-11:29:42.3 |
HIP 104654 |
1.04 |
| 2026-10-04 12:00 |
21:11:57.18 |
-11:29:50.3 |
HIP 104654 |
0.89 |
| 2026-10-05 00:00 |
21:11:56.13 |
-11:29:58.3 |
HIP 104654 |
0.81 |
| 2026-10-05 12:00 |
21:11:55.09 |
-11:30:06.3 |
HIP 104654 |
0.83 |
| 2026-10-06 00:00 |
21:11:54.07 |
-11:30:14.2 |
HIP 104654 |
0.93 |
| 2026-10-06 12:00 |
21:11:53.05 |
-11:30:22.1 |
HIP 104654 |
1.10 |
| 2026-10-07 00:00 |
21:11:52.06 |
-11:30:29.9 |
HIP 104654 |
1.31 |
| 2026-10-07 12:00 |
21:11:51.08 |
-11:30:37.6 |
HIP 104654 |
1.53 |
| 2026-10-08 00:00 |
21:11:50.11 |
-11:30:45.3 |
HIP 104654 |
1.77 |
| 2026-10-08 12:00 |
21:11:49.16 |
-11:30:52.9 |
HIP 104654 |
2.01 |
| 2026-10-09 00:00 |
21:11:48.22 |
-11:31:00.5 |
HIP 104654 |
2.25 |
| 2026-10-09 12:00 |
21:11:47.30 |
-11:31:08.0 |
HIP 104654 |
2.49 |
| 2026-10-10 00:00 |
21:11:46.39 |
-11:31:15.4 |
HIP 104654 |
2.73 |
| 2026-10-10 12:00 |
21:11:45.50 |
-11:31:22.8 |
HIP 104654 |
2.97 |
| 2026-10-11 00:00 |
21:11:44.62 |
-11:31:30.2 |
HIP 104654 |
3.21 |