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) |
| 2026-03-26 00:00 |
17:30:36.67 |
-14:31:25.0 |
HIP 85679 |
14.98 |
| 2026-03-26 12:00 |
17:30:36.29 |
-14:31:19.7 |
HIP 85679 |
15.06 |
| 2026-03-27 00:00 |
17:30:35.90 |
-14:31:14.3 |
HIP 85679 |
15.14 |
| 2026-03-27 12:00 |
17:30:35.48 |
-14:31:08.9 |
HIP 85679 |
15.23 |
| 2026-03-28 00:00 |
17:30:35.05 |
-14:31:03.6 |
HIP 85679 |
15.31 |
| 2026-03-28 12:00 |
17:30:34.60 |
-14:30:58.2 |
HIP 85679 |
15.40 |
| 2026-03-29 00:00 |
17:30:34.13 |
-14:30:52.8 |
HIP 85679 |
15.48 |
| 2026-03-29 12:00 |
17:30:33.64 |
-14:30:47.4 |
HIP 85679 |
15.57 |
| 2026-03-30 00:00 |
17:30:33.13 |
-14:30:42.1 |
HIP 85679 |
15.66 |
| 2026-03-30 12:00 |
17:30:32.61 |
-14:30:36.7 |
HIP 85679 |
15.74 |
| 2026-03-31 00:00 |
17:30:32.06 |
-14:30:31.3 |
HIP 85679 |
15.83 |
| 2026-03-31 12:00 |
17:30:31.50 |
-14:30:25.9 |
HIP 85679 |
15.92 |
| 2026-04-01 00:00 |
17:30:30.91 |
-14:30:20.5 |
HIP 85679 |
16.02 |
| 2026-04-01 12:00 |
17:30:30.31 |
-14:30:15.1 |
HIP 85679 |
16.11 |
| 2026-04-02 00:00 |
17:30:29.69 |
-14:30:09.7 |
HIP 85679 |
16.20 |
| 2026-04-02 12:00 |
17:30:29.05 |
-14:30:04.3 |
HIP 85679 |
16.30 |
| 2026-04-03 00:00 |
17:30:28.40 |
-14:29:58.9 |
HIP 85679 |
16.40 |
| 2026-04-03 12:00 |
17:30:27.72 |
-14:29:53.5 |
HIP 85679 |
16.50 |
| 2026-04-04 00:00 |
17:30:27.03 |
-14:29:48.1 |
HIP 85679 |
16.60 |
| 2026-04-04 12:00 |
17:30:26.32 |
-14:29:42.7 |
HIP 85679 |
16.70 |
| 2026-04-05 00:00 |
17:30:25.59 |
-14:29:37.3 |
HIP 85679 |
16.81 |
| 2026-04-05 12:00 |
17:30:24.84 |
-14:29:31.9 |
HIP 85679 |
16.92 |
| 2026-04-06 00:00 |
17:30:24.07 |
-14:29:26.5 |
HIP 85679 |
17.02 |
| 2026-04-06 12:00 |
17:30:23.29 |
-14:29:21.1 |
HIP 85679 |
17.14 |
| 2026-04-07 00:00 |
17:30:22.48 |
-14:29:15.7 |
HIP 85679 |
17.25 |
| 2026-04-07 12:00 |
17:30:21.66 |
-14:29:10.3 |
HIP 85679 |
17.37 |
| 2026-04-08 00:00 |
17:30:20.82 |
-14:29:04.9 |
HIP 85679 |
17.49 |
| 2026-04-08 12:00 |
17:30:19.97 |
-14:28:59.6 |
HIP 85679 |
17.61 |
| 2026-04-09 00:00 |
17:30:19.09 |
-14:28:54.2 |
HIP 85679 |
17.73 |
| 2026-04-09 12:00 |
17:30:18.20 |
-14:28:48.8 |
HIP 85679 |
17.86 |
| 2026-04-10 00:00 |
17:30:17.29 |
-14:28:43.4 |
HIP 85679 |
17.99 |
| 2026-04-10 12:00 |
17:30:16.36 |
-14:28:38.1 |
HIP 85679 |
18.13 |
| 2026-04-11 00:00 |
17:30:15.42 |
-14:28:32.7 |
HIP 85679 |
18.26 |
| 2026-04-11 12:00 |
17:30:14.46 |
-14:28:27.3 |
HIP 85679 |
18.40 |
| 2026-04-12 00:00 |
17:30:13.48 |
-14:28:22.0 |
HIP 85679 |
18.55 |
| 2026-04-12 12:00 |
17:30:12.48 |
-14:28:16.6 |
HIP 85679 |
18.69 |
| 2026-04-13 00:00 |
17:30:11.47 |
-14:28:11.3 |
HIP 85679 |
18.84 |
| 2026-04-13 12:00 |
17:30:10.44 |
-14:28:05.9 |
HIP 85679 |
19.00 |
| 2026-04-14 00:00 |
17:30:09.39 |
-14:28:00.6 |
HIP 85679 |
19.15 |
| 2026-04-14 12:00 |
17:30:08.32 |
-14:27:55.3 |
HIP 85679 |
19.31 |
| 2026-04-15 00:00 |
17:30:07.24 |
-14:27:50.0 |
HIP 85679 |
19.48 |
| 2026-04-15 12:00 |
17:30:06.14 |
-14:27:44.7 |
HIP 85679 |
19.64 |
| 2026-04-16 00:00 |
17:30:05.02 |
-14:27:39.4 |
HIP 85679 |
19.82 |