メタデータ
| 項目 |
値 |
| Designation |
C/1999 U4 (Catalina-Skiff) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2001-10-28T12:49:53.112000Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:02Z |
| Obs used |
847 |
| NEO |
- |
| M1 |
10.300 |
| K1 |
4.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2002-01-01.0000000 |
| e |
1.00756946 |
| q (au) |
4.915350 |
| a (au) |
-649.365763 |
| i (deg) |
51.925991 |
| Ω (om, deg) |
32.286666 |
| ω (w, deg) |
77.523394 |
| M (ma, deg) |
0.003840 |
等級
散乱 + 全体線形
$$
M_a = (10.223 + 3.448\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.223 |
| n |
3.448 |
| gf |
0.972 |
| gb |
-0.814 |
| k |
0.800 |
| δ90 |
9.999 |
| 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 |
| 1999-09-18 |
2001-10-23 |
+6.1426 |
-5.783 |
| 2001-11-06 |
2004-04-11 |
+1.9350 |
-1.506 |
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 |
15:10:25.53 |
-48:15:03.3 |
HIP 74285 |
16.06 |
| 2026-03-26 12:00 |
15:10:22.83 |
-48:15:14.4 |
HIP 74285 |
16.02 |
| 2026-03-27 00:00 |
15:10:20.12 |
-48:15:25.3 |
HIP 74285 |
16.00 |
| 2026-03-27 12:00 |
15:10:17.38 |
-48:15:35.9 |
HIP 74285 |
16.00 |
| 2026-03-28 00:00 |
15:10:14.61 |
-48:15:46.4 |
HIP 74285 |
16.02 |
| 2026-03-28 12:00 |
15:10:11.82 |
-48:15:56.7 |
HIP 74285 |
16.05 |
| 2026-03-29 00:00 |
15:10:09.00 |
-48:16:06.8 |
HIP 74285 |
16.11 |
| 2026-03-29 12:00 |
15:10:06.17 |
-48:16:16.7 |
HIP 74285 |
16.19 |
| 2026-03-30 00:00 |
15:10:03.30 |
-48:16:26.4 |
HIP 74285 |
16.28 |
| 2026-03-30 12:00 |
15:10:00.42 |
-48:16:35.9 |
HIP 74285 |
16.40 |
| 2026-03-31 00:00 |
15:09:57.51 |
-48:16:45.2 |
HIP 74285 |
16.53 |
| 2026-03-31 12:00 |
15:09:54.58 |
-48:16:54.3 |
HIP 74285 |
16.69 |
| 2026-04-01 00:00 |
15:09:51.62 |
-48:17:03.3 |
HIP 74285 |
16.86 |
| 2026-04-01 12:00 |
15:09:48.64 |
-48:17:12.0 |
HIP 74285 |
17.05 |
| 2026-04-02 00:00 |
15:09:45.64 |
-48:17:20.5 |
HIP 74285 |
17.26 |
| 2026-04-02 12:00 |
15:09:42.62 |
-48:17:28.8 |
HIP 74285 |
17.49 |
| 2026-04-03 00:00 |
15:09:39.58 |
-48:17:37.0 |
HIP 74285 |
17.74 |
| 2026-04-03 12:00 |
15:09:36.51 |
-48:17:44.9 |
HIP 74128 |
17.44 |
| 2026-04-04 00:00 |
15:09:33.43 |
-48:17:52.6 |
HIP 74128 |
17.13 |
| 2026-04-04 12:00 |
15:09:30.32 |
-48:18:00.2 |
HIP 74128 |
16.84 |
| 2026-04-05 00:00 |
15:09:27.19 |
-48:18:07.5 |
HIP 74128 |
16.56 |
| 2026-04-05 12:00 |
15:09:24.04 |
-48:18:14.6 |
HIP 74128 |
16.30 |
| 2026-04-06 00:00 |
15:09:20.87 |
-48:18:21.5 |
HIP 74128 |
16.05 |
| 2026-04-06 12:00 |
15:09:17.68 |
-48:18:28.3 |
HIP 74128 |
15.82 |
| 2026-04-07 00:00 |
15:09:14.47 |
-48:18:34.8 |
HIP 74128 |
15.61 |
| 2026-04-07 12:00 |
15:09:11.24 |
-48:18:41.1 |
HIP 74128 |
15.42 |
| 2026-04-08 00:00 |
15:09:07.99 |
-48:18:47.2 |
HIP 74128 |
15.24 |
| 2026-04-08 12:00 |
15:09:04.72 |
-48:18:53.1 |
HIP 74128 |
15.09 |
| 2026-04-09 00:00 |
15:09:01.44 |
-48:18:58.9 |
HIP 74128 |
14.96 |
| 2026-04-09 12:00 |
15:08:58.13 |
-48:19:04.4 |
HIP 74128 |
14.85 |
| 2026-04-10 00:00 |
15:08:54.81 |
-48:19:09.7 |
HIP 74128 |
14.77 |
| 2026-04-10 12:00 |
15:08:51.47 |
-48:19:14.7 |
HIP 74128 |
14.71 |
| 2026-04-11 00:00 |
15:08:48.11 |
-48:19:19.6 |
HIP 74128 |
14.68 |
| 2026-04-11 12:00 |
15:08:44.73 |
-48:19:24.3 |
HIP 74128 |
14.67 |
| 2026-04-12 00:00 |
15:08:41.33 |
-48:19:28.8 |
HIP 74128 |
14.68 |
| 2026-04-12 12:00 |
15:08:37.92 |
-48:19:33.1 |
HIP 74128 |
14.73 |
| 2026-04-13 00:00 |
15:08:34.49 |
-48:19:37.1 |
HIP 74128 |
14.79 |
| 2026-04-13 12:00 |
15:08:31.05 |
-48:19:41.0 |
HIP 74128 |
14.89 |
| 2026-04-14 00:00 |
15:08:27.59 |
-48:19:44.6 |
HIP 74128 |
15.01 |
| 2026-04-14 12:00 |
15:08:24.11 |
-48:19:48.1 |
HIP 74128 |
15.15 |
| 2026-04-15 00:00 |
15:08:20.62 |
-48:19:51.3 |
HIP 74128 |
15.32 |
| 2026-04-15 12:00 |
15:08:17.11 |
-48:19:54.3 |
HIP 74128 |
15.52 |
| 2026-04-16 00:00 |
15:08:13.59 |
-48:19:57.1 |
HIP 74128 |
15.74 |