C/2020 K8 (Catalina-ATLAS)
メタデータ
| 項目 |
値 |
| Designation |
C/2020 K8 (Catalina-ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-09-14T12:27:51.762240Z |
| Orbit solution date (soln_date, UTC) |
2021-05-31T22:42:54Z |
| Obs used |
291 |
| NEO |
- |
| M1 |
16.800 |
| K1 |
4.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2020-05-25T10:25:18.336000Z |
| Discovery magnitude (MPC) |
19.30 G |
| Discovery observatory (MPC) |
703 · Catalina Sky Survey |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2020-07-13.0000000 |
| e |
1.00015223 |
| q (au) |
0.474575 |
| a (au) |
-3117.411049 |
| i (deg) |
31.413950 |
| Ω (om, deg) |
181.516792 |
| ω (w, deg) |
260.064417 |
| M (ma, deg) |
-0.000360 |
等級
散乱 + 全体線形
$$
M_a = (17.114 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
17.114 |
| n |
2.000 |
| gf |
0.800 |
| gb |
-0.706 |
| 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 |
| 2020-05-25 |
2020-08-24 |
-0.0627 |
-0.210 |
| 2020-08-24 |
2020-08-30 |
-12.9190 |
-2.965 |
| 2021-02-12 |
2021-04-06 |
+13.2283 |
-1.458 |
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) |
| 2026-02-03 00:00 |
16:19:15.99 |
+05:36:10.2 |
HIP 79975 |
4.60 |
| 2026-02-03 12:00 |
16:19:18.99 |
+05:36:49.0 |
HIP 79975 |
4.84 |
| 2026-02-04 00:00 |
16:19:21.94 |
+05:37:28.2 |
HIP 79975 |
5.27 |
| 2026-02-04 12:00 |
16:19:24.84 |
+05:38:07.7 |
HIP 79975 |
5.84 |
| 2026-02-05 00:00 |
16:19:27.68 |
+05:38:47.5 |
HIP 79975 |
6.52 |
| 2026-02-05 12:00 |
16:19:30.47 |
+05:39:27.6 |
HIP 79975 |
7.26 |
| 2026-02-06 00:00 |
16:19:33.20 |
+05:40:07.9 |
HIP 79975 |
8.05 |
| 2026-02-06 12:00 |
16:19:35.88 |
+05:40:48.6 |
HIP 79975 |
8.87 |
| 2026-02-07 00:00 |
16:19:38.50 |
+05:41:29.6 |
HIP 80030 |
8.27 |
| 2026-02-07 12:00 |
16:19:41.07 |
+05:42:10.8 |
HIP 80030 |
7.54 |
| 2026-02-08 00:00 |
16:19:43.58 |
+05:42:52.4 |
HIP 80030 |
6.86 |
| 2026-02-08 12:00 |
16:19:46.03 |
+05:43:34.2 |
HIP 80030 |
6.27 |
| 2026-02-09 00:00 |
16:19:48.43 |
+05:44:16.3 |
HIP 80030 |
5.79 |
| 2026-02-09 12:00 |
16:19:50.77 |
+05:44:58.7 |
HIP 80030 |
5.43 |
| 2026-02-10 00:00 |
16:19:53.05 |
+05:45:41.4 |
HIP 80030 |
5.22 |
| 2026-02-10 12:00 |
16:19:55.28 |
+05:46:24.3 |
HIP 80030 |
5.19 |
| 2026-02-11 00:00 |
16:19:57.45 |
+05:47:07.5 |
HIP 80030 |
5.32 |
| 2026-02-11 12:00 |
16:19:59.56 |
+05:47:51.0 |
HIP 80030 |
5.60 |
| 2026-02-12 00:00 |
16:20:01.61 |
+05:48:34.7 |
HIP 80030 |
6.02 |
| 2026-02-12 12:00 |
16:20:03.61 |
+05:49:18.7 |
HIP 80030 |
6.54 |
| 2026-02-13 00:00 |
16:20:05.55 |
+05:50:03.0 |
HIP 80030 |
7.14 |
| 2026-02-13 12:00 |
16:20:07.42 |
+05:50:47.5 |
HIP 80030 |
7.80 |
| 2026-02-14 00:00 |
16:20:09.25 |
+05:51:32.3 |
HIP 80030 |
8.51 |
| 2026-02-14 12:00 |
16:20:11.01 |
+05:52:17.3 |
HIP 80030 |
9.24 |
| 2026-02-15 00:00 |
16:20:12.71 |
+05:53:02.6 |
HIP 80030 |
10.00 |
| 2026-02-15 12:00 |
16:20:14.36 |
+05:53:48.1 |
HIP 80030 |
10.78 |
| 2026-02-16 00:00 |
16:20:15.94 |
+05:54:33.8 |
HIP 80030 |
11.58 |
| 2026-02-16 12:00 |
16:20:17.47 |
+05:55:19.8 |
HIP 80030 |
12.38 |
| 2026-02-17 00:00 |
16:20:18.93 |
+05:56:06.0 |
HIP 80030 |
13.20 |
| 2026-02-17 12:00 |
16:20:20.34 |
+05:56:52.4 |
HIP 80030 |
14.02 |
| 2026-02-18 00:00 |
16:20:21.69 |
+05:57:39.1 |
HIP 80030 |
14.84 |
| 2026-02-18 12:00 |
16:20:22.97 |
+05:58:26.0 |
HIP 80030 |
15.67 |
| 2026-02-19 00:00 |
16:20:24.20 |
+05:59:13.1 |
HIP 80030 |
16.49 |
| 2026-02-19 12:00 |
16:20:25.37 |
+06:00:00.4 |
HIP 80030 |
17.33 |
| 2026-02-20 00:00 |
16:20:26.47 |
+06:00:48.0 |
HIP 80030 |
18.16 |
| 2026-02-20 12:00 |
16:20:27.52 |
+06:01:35.7 |
HIP 80030 |
18.99 |
| 2026-02-21 00:00 |
16:20:28.51 |
+06:02:23.6 |
HIP 80030 |
19.82 |
| 2026-02-21 12:00 |
16:20:29.43 |
+06:03:11.8 |
HIP 80030 |
20.66 |
| 2026-02-22 00:00 |
16:20:30.30 |
+06:04:00.1 |
HIP 80030 |
21.49 |
| 2026-02-22 12:00 |
16:20:31.10 |
+06:04:48.6 |
HIP 80030 |
22.32 |
| 2026-02-23 00:00 |
16:20:31.84 |
+06:05:37.4 |
HIP 80030 |
23.16 |
| 2026-02-23 12:00 |
16:20:32.53 |
+06:06:26.3 |
HIP 80030 |
23.99 |
| 2026-02-24 00:00 |
16:20:33.15 |
+06:07:15.3 |
HIP 80030 |
24.82 |