メタデータ
| 項目 |
値 |
| Designation |
C/2009 U3 (Hill) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2010-03-20T06:06:49.440960Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:36Z |
| Obs used |
602 |
| NEO |
- |
| M1 |
15.400 |
| K1 |
6.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2010-01-01.0000000 |
| e |
0.99157651 |
| q (au) |
1.414425 |
| a (au) |
167.914294 |
| i (deg) |
51.260767 |
| Ω (om, deg) |
49.322883 |
| ω (w, deg) |
77.701400 |
| M (ma, deg) |
359.964553 |
等級
散乱 + 全体線形
$$
M_a = (13.668 + 5.160\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
13.668 |
| n |
5.160 |
| gf |
1.000 |
| gb |
-0.772 |
| k |
0.984 |
| δ90 |
9.994 |
| 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 |
| 2009-10-20 |
2009-11-16 |
-11.6949 |
+4.120 |
| 2009-11-16 |
2009-12-24 |
+7.8048 |
-2.355 |
| 2009-12-24 |
2010-01-26 |
-15.1111 |
+3.692 |
| 2010-01-26 |
2010-03-19 |
+34.3857 |
-6.645 |
| 2010-03-24 |
2010-05-14 |
+6.6096 |
-1.956 |
| 2010-05-14 |
2010-06-18 |
-14.3864 |
+3.611 |
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) |
| 2026-09-20 00:00 |
17:55:52.68 |
-63:27:40.3 |
HIP 87704 |
13.06 |
| 2026-09-20 12:00 |
17:55:52.87 |
-63:27:08.7 |
HIP 87704 |
12.62 |
| 2026-09-21 00:00 |
17:55:53.13 |
-63:26:37.0 |
HIP 87704 |
12.20 |
| 2026-09-21 12:00 |
17:55:53.45 |
-63:26:05.4 |
HIP 87704 |
11.79 |
| 2026-09-22 00:00 |
17:55:53.84 |
-63:25:33.8 |
HIP 87704 |
11.40 |
| 2026-09-22 12:00 |
17:55:54.29 |
-63:25:02.2 |
HIP 87704 |
11.02 |
| 2026-09-23 00:00 |
17:55:54.81 |
-63:24:30.6 |
HIP 87704 |
10.66 |
| 2026-09-23 12:00 |
17:55:55.39 |
-63:23:59.1 |
HIP 87704 |
10.32 |
| 2026-09-24 00:00 |
17:55:56.04 |
-63:23:27.5 |
HIP 87704 |
10.00 |
| 2026-09-24 12:00 |
17:55:56.75 |
-63:22:56.0 |
HIP 87704 |
9.70 |
| 2026-09-25 00:00 |
17:55:57.53 |
-63:22:24.6 |
HIP 87704 |
9.43 |
| 2026-09-25 12:00 |
17:55:58.37 |
-63:21:53.1 |
HIP 87704 |
9.19 |
| 2026-09-26 00:00 |
17:55:59.27 |
-63:21:21.7 |
HIP 87704 |
8.99 |
| 2026-09-26 12:00 |
17:56:00.24 |
-63:20:50.3 |
HIP 87704 |
8.81 |
| 2026-09-27 00:00 |
17:56:01.28 |
-63:20:19.0 |
HIP 87704 |
8.68 |
| 2026-09-27 12:00 |
17:56:02.37 |
-63:19:47.7 |
HIP 87704 |
8.58 |
| 2026-09-28 00:00 |
17:56:03.53 |
-63:19:16.4 |
HIP 87704 |
8.52 |
| 2026-09-28 12:00 |
17:56:04.76 |
-63:18:45.2 |
HIP 87704 |
8.50 |
| 2026-09-29 00:00 |
17:56:06.05 |
-63:18:14.1 |
HIP 87704 |
8.53 |
| 2026-09-29 12:00 |
17:56:07.40 |
-63:17:42.9 |
HIP 87704 |
8.59 |
| 2026-09-30 00:00 |
17:56:08.82 |
-63:17:11.9 |
HIP 87704 |
8.70 |
| 2026-09-30 12:00 |
17:56:10.29 |
-63:16:40.8 |
HIP 87704 |
8.84 |
| 2026-10-01 00:00 |
17:56:11.84 |
-63:16:09.9 |
HIP 87704 |
9.02 |
| 2026-10-01 12:00 |
17:56:13.44 |
-63:15:39.0 |
HIP 87704 |
9.24 |
| 2026-10-02 00:00 |
17:56:15.11 |
-63:15:08.1 |
HIP 87704 |
9.49 |
| 2026-10-02 12:00 |
17:56:16.84 |
-63:14:37.3 |
HIP 87868 |
9.03 |
| 2026-10-03 00:00 |
17:56:18.63 |
-63:14:06.6 |
HIP 87868 |
8.49 |
| 2026-10-03 12:00 |
17:56:20.49 |
-63:13:35.9 |
HIP 87868 |
7.94 |
| 2026-10-04 00:00 |
17:56:22.40 |
-63:13:05.3 |
HIP 87868 |
7.39 |
| 2026-10-04 12:00 |
17:56:24.38 |
-63:12:34.8 |
HIP 87868 |
6.84 |
| 2026-10-05 00:00 |
17:56:26.42 |
-63:12:04.3 |
HIP 87868 |
6.29 |
| 2026-10-05 12:00 |
17:56:28.53 |
-63:11:33.9 |
HIP 87868 |
5.74 |
| 2026-10-06 00:00 |
17:56:30.69 |
-63:11:03.6 |
HIP 87868 |
5.18 |
| 2026-10-06 12:00 |
17:56:32.92 |
-63:10:33.4 |
HIP 87868 |
4.62 |
| 2026-10-07 00:00 |
17:56:35.21 |
-63:10:03.3 |
HIP 87868 |
4.06 |
| 2026-10-07 12:00 |
17:56:37.56 |
-63:09:33.2 |
HIP 87868 |
3.50 |
| 2026-10-08 00:00 |
17:56:39.97 |
-63:09:03.2 |
HIP 87868 |
2.94 |
| 2026-10-08 12:00 |
17:56:42.44 |
-63:08:33.3 |
HIP 87868 |
2.38 |
| 2026-10-09 00:00 |
17:56:44.97 |
-63:08:03.5 |
HIP 87868 |
1.82 |
| 2026-10-09 12:00 |
17:56:47.56 |
-63:07:33.8 |
HIP 87868 |
1.27 |
| 2026-10-10 00:00 |
17:56:50.21 |
-63:07:04.2 |
HIP 87868 |
0.75 |
| 2026-10-10 12:00 |
17:56:52.93 |
-63:06:34.6 |
HIP 87868 |
0.43 |
| 2026-10-11 00:00 |
17:56:55.70 |
-63:06:05.2 |
HIP 87868 |
0.68 |