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) |
| 2026-07-29 00:00 |
21:15:42.69 |
-11:07:54.4 |
HIP 104808 |
24.99 |
| 2026-07-29 12:00 |
21:15:40.80 |
-11:08:03.9 |
HIP 104808 |
24.51 |
| 2026-07-30 00:00 |
21:15:38.91 |
-11:08:13.4 |
HIP 104808 |
24.03 |
| 2026-07-30 12:00 |
21:15:37.02 |
-11:08:22.9 |
HIP 104808 |
23.55 |
| 2026-07-31 00:00 |
21:15:35.13 |
-11:08:32.5 |
HIP 104808 |
23.07 |
| 2026-07-31 12:00 |
21:15:33.23 |
-11:08:42.1 |
HIP 104808 |
22.59 |
| 2026-08-01 00:00 |
21:15:31.33 |
-11:08:51.7 |
HIP 104808 |
22.11 |
| 2026-08-01 12:00 |
21:15:29.43 |
-11:09:01.4 |
HIP 104808 |
21.64 |
| 2026-08-02 00:00 |
21:15:27.53 |
-11:09:11.1 |
HIP 104808 |
21.16 |
| 2026-08-02 12:00 |
21:15:25.62 |
-11:09:20.8 |
HIP 104808 |
20.68 |
| 2026-08-03 00:00 |
21:15:23.71 |
-11:09:30.5 |
HIP 104808 |
20.20 |
| 2026-08-03 12:00 |
21:15:21.80 |
-11:09:40.3 |
HIP 104808 |
19.72 |
| 2026-08-04 00:00 |
21:15:19.89 |
-11:09:50.1 |
HIP 104808 |
19.24 |
| 2026-08-04 12:00 |
21:15:17.98 |
-11:10:00.0 |
HIP 104808 |
18.77 |
| 2026-08-05 00:00 |
21:15:16.07 |
-11:10:09.8 |
HIP 104808 |
18.29 |
| 2026-08-05 12:00 |
21:15:14.15 |
-11:10:19.7 |
HIP 104808 |
17.81 |
| 2026-08-06 00:00 |
21:15:12.24 |
-11:10:29.6 |
HIP 104808 |
17.34 |
| 2026-08-06 12:00 |
21:15:10.32 |
-11:10:39.5 |
HIP 104808 |
16.87 |
| 2026-08-07 00:00 |
21:15:08.40 |
-11:10:49.5 |
HIP 104808 |
16.40 |
| 2026-08-07 12:00 |
21:15:06.48 |
-11:10:59.4 |
HIP 104808 |
15.92 |
| 2026-08-08 00:00 |
21:15:04.56 |
-11:11:09.4 |
HIP 104808 |
15.46 |
| 2026-08-08 12:00 |
21:15:02.64 |
-11:11:19.5 |
HIP 104808 |
14.99 |
| 2026-08-09 00:00 |
21:15:00.72 |
-11:11:29.5 |
HIP 104808 |
14.52 |
| 2026-08-09 12:00 |
21:14:58.80 |
-11:11:39.6 |
HIP 104808 |
14.06 |
| 2026-08-10 00:00 |
21:14:56.88 |
-11:11:49.7 |
HIP 104808 |
13.60 |
| 2026-08-10 12:00 |
21:14:54.96 |
-11:11:59.8 |
HIP 104808 |
13.15 |
| 2026-08-11 00:00 |
21:14:53.04 |
-11:12:09.9 |
HIP 104808 |
12.69 |
| 2026-08-11 12:00 |
21:14:51.13 |
-11:12:20.0 |
HIP 104808 |
12.24 |
| 2026-08-12 00:00 |
21:14:49.21 |
-11:12:30.2 |
HIP 104808 |
11.80 |
| 2026-08-12 12:00 |
21:14:47.29 |
-11:12:40.4 |
HIP 104808 |
11.36 |
| 2026-08-13 00:00 |
21:14:45.37 |
-11:12:50.6 |
HIP 104808 |
10.92 |
| 2026-08-13 12:00 |
21:14:43.46 |
-11:13:00.8 |
HIP 104808 |
10.49 |
| 2026-08-14 00:00 |
21:14:41.55 |
-11:13:11.0 |
HIP 104808 |
10.07 |
| 2026-08-14 12:00 |
21:14:39.63 |
-11:13:21.2 |
HIP 104808 |
9.66 |
| 2026-08-15 00:00 |
21:14:37.72 |
-11:13:31.4 |
HIP 104808 |
9.25 |
| 2026-08-15 12:00 |
21:14:35.81 |
-11:13:41.7 |
HIP 104808 |
8.86 |
| 2026-08-16 00:00 |
21:14:33.91 |
-11:13:52.0 |
HIP 104808 |
8.47 |
| 2026-08-16 12:00 |
21:14:32.00 |
-11:14:02.2 |
HIP 104808 |
8.10 |
| 2026-08-17 00:00 |
21:14:30.10 |
-11:14:12.5 |
HIP 104808 |
7.74 |
| 2026-08-17 12:00 |
21:14:28.20 |
-11:14:22.8 |
HIP 104808 |
7.40 |
| 2026-08-18 00:00 |
21:14:26.30 |
-11:14:33.1 |
HIP 104808 |
7.08 |
| 2026-08-18 12:00 |
21:14:24.41 |
-11:14:43.4 |
HIP 104808 |
6.79 |
| 2026-08-19 00:00 |
21:14:22.51 |
-11:14:53.8 |
HIP 104808 |
6.51 |