メタデータ
| 項目 |
値 |
| Designation |
C/2017 S6 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-02-26T22:22:53.693760Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:35Z |
| Obs used |
247 |
| NEO |
- |
| M1 |
15.300 |
| K1 |
4.750 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2017-11-15.0000000 |
| e |
1.00140730 |
| q (au) |
1.542930 |
| a (au) |
-1096.375698 |
| i (deg) |
152.826812 |
| Ω (om, deg) |
130.873122 |
| ω (w, deg) |
134.685410 |
| M (ma, deg) |
-0.002822 |
等級
散乱 + 全体線形
$$
M_a = (17.010 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
17.010 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.676 |
| k |
0.800 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2017-02-16 |
2017-10-28 |
+4.8973 |
-2.493 |
| 2017-10-28 |
2018-02-05 |
+7.2164 |
-2.343 |
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) |
| 2026-06-01 00:00 |
12:40:08.47 |
-34:02:39.7 |
HIP 61757 |
16.43 |
| 2026-06-01 12:00 |
12:40:04.90 |
-34:01:45.8 |
HIP 61757 |
15.27 |
| 2026-06-02 00:00 |
12:40:01.38 |
-34:00:51.9 |
HIP 61757 |
14.12 |
| 2026-06-02 12:00 |
12:39:57.91 |
-33:59:58.1 |
HIP 61757 |
12.98 |
| 2026-06-03 00:00 |
12:39:54.49 |
-33:59:04.3 |
HIP 61757 |
11.85 |
| 2026-06-03 12:00 |
12:39:51.12 |
-33:58:10.6 |
HIP 61757 |
10.73 |
| 2026-06-04 00:00 |
12:39:47.79 |
-33:57:17.0 |
HIP 61757 |
9.61 |
| 2026-06-04 12:00 |
12:39:44.52 |
-33:56:23.5 |
HIP 61757 |
8.50 |
| 2026-06-05 00:00 |
12:39:41.30 |
-33:55:30.1 |
HIP 61757 |
7.41 |
| 2026-06-05 12:00 |
12:39:38.12 |
-33:54:36.8 |
HIP 61757 |
6.32 |
| 2026-06-06 00:00 |
12:39:35.00 |
-33:53:43.6 |
HIP 61757 |
5.25 |
| 2026-06-06 12:00 |
12:39:31.93 |
-33:52:50.4 |
HIP 61757 |
4.20 |
| 2026-06-07 00:00 |
12:39:28.91 |
-33:51:57.4 |
HIP 61757 |
3.18 |
| 2026-06-07 12:00 |
12:39:25.93 |
-33:51:04.5 |
HIP 61757 |
2.22 |
| 2026-06-08 00:00 |
12:39:23.01 |
-33:50:11.7 |
HIP 61757 |
1.44 |
| 2026-06-08 12:00 |
12:39:20.14 |
-33:49:19.0 |
HIP 61757 |
1.21 |
| 2026-06-09 00:00 |
12:39:17.32 |
-33:48:26.4 |
HIP 61757 |
1.75 |
| 2026-06-09 12:00 |
12:39:14.55 |
-33:47:34.0 |
HIP 61757 |
2.62 |
| 2026-06-10 00:00 |
12:39:11.84 |
-33:46:41.7 |
HIP 61757 |
3.57 |
| 2026-06-10 12:00 |
12:39:09.17 |
-33:45:49.5 |
HIP 61757 |
4.55 |
| 2026-06-11 00:00 |
12:39:06.56 |
-33:44:57.4 |
HIP 61757 |
5.55 |
| 2026-06-11 12:00 |
12:39:03.99 |
-33:44:05.5 |
HIP 61757 |
6.54 |
| 2026-06-12 00:00 |
12:39:01.48 |
-33:43:13.8 |
HIP 61757 |
7.53 |
| 2026-06-12 12:00 |
12:38:59.02 |
-33:42:22.1 |
HIP 61757 |
8.51 |
| 2026-06-13 00:00 |
12:38:56.61 |
-33:41:30.6 |
HIP 61757 |
9.49 |
| 2026-06-13 12:00 |
12:38:54.25 |
-33:40:39.3 |
HIP 61757 |
10.47 |
| 2026-06-14 00:00 |
12:38:51.95 |
-33:39:48.2 |
HIP 61757 |
11.43 |
| 2026-06-14 12:00 |
12:38:49.70 |
-33:38:57.2 |
HIP 61757 |
12.39 |
| 2026-06-15 00:00 |
12:38:47.50 |
-33:38:06.3 |
HIP 61757 |
13.35 |
| 2026-06-15 12:00 |
12:38:45.35 |
-33:37:15.7 |
HIP 61757 |
14.29 |
| 2026-06-16 00:00 |
12:38:43.25 |
-33:36:25.2 |
HIP 61666 |
13.64 |
| 2026-06-16 12:00 |
12:38:41.21 |
-33:35:34.9 |
HIP 61666 |
12.74 |
| 2026-06-17 00:00 |
12:38:39.21 |
-33:34:44.7 |
HIP 61666 |
11.84 |
| 2026-06-17 12:00 |
12:38:37.27 |
-33:33:54.8 |
HIP 61666 |
10.95 |
| 2026-06-18 00:00 |
12:38:35.39 |
-33:33:05.0 |
HIP 61666 |
10.07 |
| 2026-06-18 12:00 |
12:38:33.55 |
-33:32:15.5 |
HIP 61666 |
9.21 |
| 2026-06-19 00:00 |
12:38:31.77 |
-33:31:26.1 |
HIP 61666 |
8.35 |
| 2026-06-19 12:00 |
12:38:30.04 |
-33:30:36.9 |
HIP 61666 |
7.52 |
| 2026-06-20 00:00 |
12:38:28.36 |
-33:29:48.0 |
HIP 61666 |
6.70 |
| 2026-06-20 12:00 |
12:38:26.73 |
-33:28:59.2 |
HIP 61666 |
5.91 |
| 2026-06-21 00:00 |
12:38:25.15 |
-33:28:10.6 |
HIP 61666 |
5.14 |
| 2026-06-21 12:00 |
12:38:23.63 |
-33:27:22.3 |
HIP 61666 |
4.42 |
| 2026-06-22 00:00 |
12:38:22.16 |
-33:26:34.2 |
HIP 61666 |
3.75 |