C/2020 K2 (PANSTARRS)
メタデータ
| 項目 |
値 |
| Designation |
C/2020 K2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-08-04T17:10:46.476480Z |
| Orbit solution date (soln_date, UTC) |
2021-07-01T22:12:49Z |
| Obs used |
87 |
| NEO |
- |
| M1 |
7.000 |
| K1 |
9.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2020-05-21T13:39:44.841600Z |
| Discovery magnitude (MPC) |
20.56 w |
| Discovery observatory (MPC) |
F52 · Pan-STARRS 2, Haleakala |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2020-07-25.0000000 |
| e |
1.00129323 |
| q (au) |
8.878219 |
| a (au) |
-6865.139277 |
| i (deg) |
91.035953 |
| Ω (om, deg) |
288.338902 |
| ω (w, deg) |
67.272622 |
| M (ma, deg) |
-0.000019 |
等級
散乱 + 全体線形
$$
M_a = (7.947 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
7.947 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.800 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
07:52:07.67 |
+61:32:25.6 |
HIP 38609 |
33.12 |
| 2026-02-03 12:00 |
07:51:48.95 |
+61:31:38.0 |
HIP 38609 |
33.60 |
| 2026-02-04 00:00 |
07:51:30.30 |
+61:30:49.5 |
HIP 38609 |
34.23 |
| 2026-02-04 12:00 |
07:51:11.73 |
+61:30:00.2 |
HIP 38609 |
34.98 |
| 2026-02-05 00:00 |
07:50:53.25 |
+61:29:09.9 |
HIP 37903 |
35.54 |
| 2026-02-05 12:00 |
07:50:34.85 |
+61:28:18.8 |
HIP 37903 |
33.22 |
| 2026-02-06 00:00 |
07:50:16.54 |
+61:27:26.8 |
HIP 37903 |
30.91 |
| 2026-02-06 12:00 |
07:49:58.32 |
+61:26:33.9 |
HIP 37903 |
28.62 |
| 2026-02-07 00:00 |
07:49:40.19 |
+61:25:40.2 |
HIP 37903 |
26.34 |
| 2026-02-07 12:00 |
07:49:22.14 |
+61:24:45.6 |
HIP 37903 |
24.08 |
| 2026-02-08 00:00 |
07:49:04.20 |
+61:23:50.1 |
HIP 37903 |
21.85 |
| 2026-02-08 12:00 |
07:48:46.34 |
+61:22:53.8 |
HIP 37903 |
19.65 |
| 2026-02-09 00:00 |
07:48:28.58 |
+61:21:56.6 |
HIP 37903 |
17.50 |
| 2026-02-09 12:00 |
07:48:10.92 |
+61:20:58.6 |
HIP 37903 |
15.41 |
| 2026-02-10 00:00 |
07:47:53.36 |
+61:19:59.8 |
HIP 37903 |
13.40 |
| 2026-02-10 12:00 |
07:47:35.91 |
+61:19:00.1 |
HIP 37903 |
11.54 |
| 2026-02-11 00:00 |
07:47:18.55 |
+61:17:59.6 |
HIP 37903 |
9.87 |
| 2026-02-11 12:00 |
07:47:01.30 |
+61:16:58.2 |
HIP 37903 |
8.54 |
| 2026-02-12 00:00 |
07:46:44.15 |
+61:15:56.1 |
HIP 37903 |
7.69 |
| 2026-02-12 12:00 |
07:46:27.12 |
+61:14:53.1 |
HIP 37903 |
7.50 |
| 2026-02-13 00:00 |
07:46:10.19 |
+61:13:49.3 |
HIP 37903 |
8.02 |
| 2026-02-13 12:00 |
07:45:53.37 |
+61:12:44.8 |
HIP 37903 |
9.11 |
| 2026-02-14 00:00 |
07:45:36.66 |
+61:11:39.4 |
HIP 37903 |
10.59 |
| 2026-02-14 12:00 |
07:45:20.07 |
+61:10:33.2 |
HIP 37903 |
12.34 |
| 2026-02-15 00:00 |
07:45:03.59 |
+61:09:26.3 |
HIP 37903 |
14.24 |
| 2026-02-15 12:00 |
07:44:47.23 |
+61:08:18.6 |
HIP 37595 |
14.13 |
| 2026-02-16 00:00 |
07:44:30.99 |
+61:07:10.1 |
HIP 37595 |
12.34 |
| 2026-02-16 12:00 |
07:44:14.86 |
+61:06:00.8 |
HIP 37595 |
10.75 |
| 2026-02-17 00:00 |
07:43:58.86 |
+61:04:50.8 |
HIP 37595 |
9.45 |
| 2026-02-17 12:00 |
07:43:42.98 |
+61:03:40.1 |
HIP 37595 |
8.58 |
| 2026-02-18 00:00 |
07:43:27.22 |
+61:02:28.6 |
HIP 37595 |
8.26 |
| 2026-02-18 12:00 |
07:43:11.58 |
+61:01:16.3 |
HIP 37595 |
8.56 |
| 2026-02-19 00:00 |
07:42:56.07 |
+61:00:03.4 |
HIP 37595 |
9.41 |
| 2026-02-19 12:00 |
07:42:40.69 |
+60:58:49.7 |
HIP 37595 |
10.68 |
| 2026-02-20 00:00 |
07:42:25.44 |
+60:57:35.3 |
HIP 37595 |
12.24 |
| 2026-02-20 12:00 |
07:42:10.31 |
+60:56:20.1 |
HIP 37595 |
13.98 |
| 2026-02-21 00:00 |
07:41:55.31 |
+60:55:04.3 |
HIP 37595 |
15.85 |
| 2026-02-21 12:00 |
07:41:40.45 |
+60:53:47.8 |
HIP 37595 |
17.80 |
| 2026-02-22 00:00 |
07:41:25.72 |
+60:52:30.6 |
HIP 37510 |
18.81 |
| 2026-02-22 12:00 |
07:41:11.12 |
+60:51:12.8 |
HIP 37510 |
17.98 |
| 2026-02-23 00:00 |
07:40:56.65 |
+60:49:54.2 |
HIP 37510 |
17.37 |
| 2026-02-23 12:00 |
07:40:42.32 |
+60:48:35.0 |
HIP 37510 |
17.00 |
| 2026-02-24 00:00 |
07:40:28.12 |
+60:47:15.2 |
HIP 37510 |
16.90 |