メタデータ
| 項目 |
値 |
| Designation |
C/2018 W1 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-05-11T20:28:13.800000Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:48Z |
| Obs used |
287 |
| NEO |
- |
| M1 |
14.000 |
| K1 |
10.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2018-11-16T04:47:27.168000Z |
| Discovery magnitude (MPC) |
19.80 G |
| Discovery observatory (MPC) |
703 · University of Arizona Catalina Sky Survey |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2019-01-26.0000000 |
| e |
0.93766329 |
| q (au) |
1.360177 |
| a (au) |
21.819838 |
| i (deg) |
83.278879 |
| Ω (om, deg) |
233.589579 |
| ω (w, deg) |
251.248066 |
| M (ma, deg) |
358.976401 |
等級
散乱 + 全体線形
$$
M_a = (11.588 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
11.588 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.941 |
| k |
0.999 |
| 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 |
| 2018-11-16 |
2019-03-08 |
-1.4661 |
+0.573 |
| 2019-05-26 |
2020-05-21 |
+6.2919 |
-4.653 |
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) |
| 2026-07-29 00:00 |
16:19:08.42 |
+26:18:13.8 |
HIP 79917 |
17.24 |
| 2026-07-29 12:00 |
16:19:05.00 |
+26:17:23.4 |
HIP 79917 |
16.20 |
| 2026-07-30 00:00 |
16:19:01.65 |
+26:16:32.7 |
HIP 79917 |
15.18 |
| 2026-07-30 12:00 |
16:18:58.36 |
+26:15:41.6 |
HIP 79917 |
14.18 |
| 2026-07-31 00:00 |
16:18:55.12 |
+26:14:50.1 |
HIP 79917 |
13.18 |
| 2026-07-31 12:00 |
16:18:51.94 |
+26:13:58.3 |
HIP 79917 |
12.21 |
| 2026-08-01 00:00 |
16:18:48.82 |
+26:13:06.1 |
HIP 79917 |
11.26 |
| 2026-08-01 12:00 |
16:18:45.76 |
+26:12:13.6 |
HIP 79917 |
10.34 |
| 2026-08-02 00:00 |
16:18:42.75 |
+26:11:20.8 |
HIP 79917 |
9.46 |
| 2026-08-02 12:00 |
16:18:39.81 |
+26:10:27.6 |
HIP 79917 |
8.62 |
| 2026-08-03 00:00 |
16:18:36.92 |
+26:09:34.1 |
HIP 79917 |
7.84 |
| 2026-08-03 12:00 |
16:18:34.09 |
+26:08:40.3 |
HIP 79917 |
7.13 |
| 2026-08-04 00:00 |
16:18:31.32 |
+26:07:46.1 |
HIP 79917 |
6.53 |
| 2026-08-04 12:00 |
16:18:28.61 |
+26:06:51.7 |
HIP 79917 |
6.05 |
| 2026-08-05 00:00 |
16:18:25.96 |
+26:05:56.9 |
HIP 79917 |
5.73 |
| 2026-08-05 12:00 |
16:18:23.37 |
+26:05:01.8 |
HIP 79917 |
5.59 |
| 2026-08-06 00:00 |
16:18:20.84 |
+26:04:06.5 |
HIP 79917 |
5.65 |
| 2026-08-06 12:00 |
16:18:18.37 |
+26:03:10.8 |
HIP 79917 |
5.89 |
| 2026-08-07 00:00 |
16:18:15.96 |
+26:02:14.8 |
HIP 79917 |
6.30 |
| 2026-08-07 12:00 |
16:18:13.61 |
+26:01:18.6 |
HIP 79917 |
6.84 |
| 2026-08-08 00:00 |
16:18:11.32 |
+26:00:22.1 |
HIP 79889 |
7.13 |
| 2026-08-08 12:00 |
16:18:09.09 |
+25:59:25.3 |
HIP 79889 |
6.51 |
| 2026-08-09 00:00 |
16:18:06.92 |
+25:58:28.3 |
HIP 79889 |
6.00 |
| 2026-08-09 12:00 |
16:18:04.81 |
+25:57:30.9 |
HIP 79889 |
5.64 |
| 2026-08-10 00:00 |
16:18:02.76 |
+25:56:33.3 |
HIP 79889 |
5.45 |
| 2026-08-10 12:00 |
16:18:00.78 |
+25:55:35.5 |
HIP 79889 |
5.45 |
| 2026-08-11 00:00 |
16:17:58.85 |
+25:54:37.4 |
HIP 79889 |
5.64 |
| 2026-08-11 12:00 |
16:17:56.99 |
+25:53:39.1 |
HIP 79889 |
6.00 |
| 2026-08-12 00:00 |
16:17:55.19 |
+25:52:40.5 |
HIP 79889 |
6.50 |
| 2026-08-12 12:00 |
16:17:53.45 |
+25:51:41.8 |
HIP 79889 |
7.11 |
| 2026-08-13 00:00 |
16:17:51.77 |
+25:50:42.7 |
HIP 79889 |
7.81 |
| 2026-08-13 12:00 |
16:17:50.15 |
+25:49:43.5 |
HIP 79889 |
8.57 |
| 2026-08-14 00:00 |
16:17:48.60 |
+25:48:44.1 |
HIP 79889 |
9.38 |
| 2026-08-14 12:00 |
16:17:47.10 |
+25:47:44.4 |
HIP 79889 |
10.22 |
| 2026-08-15 00:00 |
16:17:45.67 |
+25:46:44.5 |
HIP 79889 |
11.09 |
| 2026-08-15 12:00 |
16:17:44.30 |
+25:45:44.5 |
HIP 79889 |
11.98 |
| 2026-08-16 00:00 |
16:17:42.99 |
+25:44:44.2 |
HIP 79889 |
12.88 |
| 2026-08-16 12:00 |
16:17:41.74 |
+25:43:43.8 |
HIP 79889 |
13.80 |
| 2026-08-17 00:00 |
16:17:40.56 |
+25:42:43.2 |
HIP 79889 |
14.73 |
| 2026-08-17 12:00 |
16:17:39.44 |
+25:41:42.4 |
HIP 79889 |
15.66 |
| 2026-08-18 00:00 |
16:17:38.37 |
+25:40:41.4 |
HIP 79889 |
16.61 |
| 2026-08-18 12:00 |
16:17:37.38 |
+25:39:40.3 |
HIP 79889 |
17.56 |
| 2026-08-19 00:00 |
16:17:36.44 |
+25:38:39.0 |
HIP 79889 |
18.51 |