メタデータ
| 項目 |
値 |
| Designation |
C/1984 U2 (Shoemaker) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1985-01-03T21:17:59.058240Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:31Z |
| Obs used |
147 |
| NEO |
- |
| M1 |
10.100 |
| K1 |
20.750 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1985-01-03.0000000 |
| e |
0.97091010 |
| q (au) |
1.214513 |
| a (au) |
41.750335 |
| i (deg) |
13.881367 |
| Ω (om, deg) |
223.475527 |
| ω (w, deg) |
229.212904 |
| M (ma, deg) |
359.996758 |
等級
散乱 + 全体線形
$$
M_a = (11.650 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
11.650 |
| n |
6.000 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.827 |
| δ90 |
1.000 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 1984-10-25 |
1985-01-02 |
-8.6747 |
+1.412 |
| 1985-01-04 |
1985-03-13 |
+0.7232 |
+0.888 |
log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
17:28:46.63 |
-14:23:25.8 |
HIP 85471 |
13.83 |
| 2026-05-12 12:00 |
17:28:44.78 |
-14:23:21.5 |
HIP 85471 |
13.41 |
| 2026-05-13 00:00 |
17:28:42.93 |
-14:23:17.2 |
HIP 85471 |
13.00 |
| 2026-05-13 12:00 |
17:28:41.07 |
-14:23:12.9 |
HIP 85471 |
12.58 |
| 2026-05-14 00:00 |
17:28:39.20 |
-14:23:08.7 |
HIP 85471 |
12.17 |
| 2026-05-14 12:00 |
17:28:37.31 |
-14:23:04.5 |
HIP 85471 |
11.76 |
| 2026-05-15 00:00 |
17:28:35.42 |
-14:23:00.3 |
HIP 85471 |
11.35 |
| 2026-05-15 12:00 |
17:28:33.52 |
-14:22:56.2 |
HIP 85471 |
10.94 |
| 2026-05-16 00:00 |
17:28:31.61 |
-14:22:52.1 |
HIP 85471 |
10.54 |
| 2026-05-16 12:00 |
17:28:29.69 |
-14:22:48.0 |
HIP 85471 |
10.14 |
| 2026-05-17 00:00 |
17:28:27.76 |
-14:22:44.0 |
HIP 85471 |
9.74 |
| 2026-05-17 12:00 |
17:28:25.82 |
-14:22:40.0 |
HIP 85471 |
9.35 |
| 2026-05-18 00:00 |
17:28:23.87 |
-14:22:36.0 |
HIP 85471 |
8.97 |
| 2026-05-18 12:00 |
17:28:21.92 |
-14:22:32.0 |
HIP 85471 |
8.60 |
| 2026-05-19 00:00 |
17:28:19.95 |
-14:22:28.1 |
HIP 85471 |
8.24 |
| 2026-05-19 12:00 |
17:28:17.98 |
-14:22:24.2 |
HIP 85471 |
7.89 |
| 2026-05-20 00:00 |
17:28:16.00 |
-14:22:20.3 |
HIP 85471 |
7.55 |
| 2026-05-20 12:00 |
17:28:14.01 |
-14:22:16.5 |
HIP 85471 |
7.23 |
| 2026-05-21 00:00 |
17:28:12.01 |
-14:22:12.7 |
HIP 85471 |
6.93 |
| 2026-05-21 12:00 |
17:28:10.01 |
-14:22:09.0 |
HIP 85471 |
6.65 |
| 2026-05-22 00:00 |
17:28:08.00 |
-14:22:05.2 |
HIP 85471 |
6.39 |
| 2026-05-22 12:00 |
17:28:05.98 |
-14:22:01.5 |
HIP 85471 |
6.16 |
| 2026-05-23 00:00 |
17:28:03.95 |
-14:21:57.9 |
HIP 85471 |
5.97 |
| 2026-05-23 12:00 |
17:28:01.92 |
-14:21:54.2 |
HIP 85471 |
5.81 |
| 2026-05-24 00:00 |
17:27:59.88 |
-14:21:50.6 |
HIP 85471 |
5.69 |
| 2026-05-24 12:00 |
17:27:57.83 |
-14:21:47.1 |
HIP 85471 |
5.62 |
| 2026-05-25 00:00 |
17:27:55.78 |
-14:21:43.5 |
HIP 85471 |
5.58 |
| 2026-05-25 12:00 |
17:27:53.72 |
-14:21:40.0 |
HIP 85471 |
5.60 |
| 2026-05-26 00:00 |
17:27:51.66 |
-14:21:36.6 |
HIP 85471 |
5.66 |
| 2026-05-26 12:00 |
17:27:49.58 |
-14:21:33.2 |
HIP 85471 |
5.76 |
| 2026-05-27 00:00 |
17:27:47.51 |
-14:21:29.8 |
HIP 85471 |
5.91 |
| 2026-05-27 12:00 |
17:27:45.42 |
-14:21:26.4 |
HIP 85471 |
6.09 |
| 2026-05-28 00:00 |
17:27:43.34 |
-14:21:23.1 |
HIP 85471 |
6.32 |
| 2026-05-28 12:00 |
17:27:41.24 |
-14:21:19.8 |
HIP 85471 |
6.57 |
| 2026-05-29 00:00 |
17:27:39.14 |
-14:21:16.6 |
HIP 85471 |
6.86 |
| 2026-05-29 12:00 |
17:27:37.04 |
-14:21:13.3 |
HIP 85471 |
7.17 |
| 2026-05-30 00:00 |
17:27:34.93 |
-14:21:10.2 |
HIP 85471 |
7.51 |
| 2026-05-30 12:00 |
17:27:32.82 |
-14:21:07.0 |
HIP 85471 |
7.86 |
| 2026-05-31 00:00 |
17:27:30.70 |
-14:21:03.9 |
HIP 85471 |
8.24 |
| 2026-05-31 12:00 |
17:27:28.58 |
-14:21:00.8 |
HIP 85471 |
8.63 |
| 2026-06-01 00:00 |
17:27:26.45 |
-14:20:57.8 |
HIP 85471 |
9.03 |
| 2026-06-01 12:00 |
17:27:24.32 |
-14:20:54.8 |
HIP 85471 |
9.45 |
| 2026-06-02 00:00 |
17:27:22.19 |
-14:20:51.9 |
HIP 85471 |
9.87 |