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
$$
M_a = (7.933 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
7.933 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-1.000 |
| k |
0.801 |
| δ90 |
9.160 |
| 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) |
| 2026-09-20 00:00 |
08:14:08.05 |
+52:55:13.0 |
HIP 40402 |
7.06 |
| 2026-09-20 12:00 |
08:14:13.57 |
+52:55:23.8 |
HIP 40402 |
6.21 |
| 2026-09-21 00:00 |
08:14:19.01 |
+52:55:35.1 |
HIP 40402 |
5.37 |
| 2026-09-21 12:00 |
08:14:24.36 |
+52:55:46.8 |
HIP 40402 |
4.54 |
| 2026-09-22 00:00 |
08:14:29.63 |
+52:55:58.9 |
HIP 40402 |
3.72 |
| 2026-09-22 12:00 |
08:14:34.81 |
+52:56:11.5 |
HIP 40402 |
2.92 |
| 2026-09-23 00:00 |
08:14:39.91 |
+52:56:24.5 |
HIP 40402 |
2.13 |
| 2026-09-23 12:00 |
08:14:44.93 |
+52:56:37.9 |
HIP 40402 |
1.36 |
| 2026-09-24 00:00 |
08:14:49.85 |
+52:56:51.8 |
HIP 40402 |
0.66 |
| 2026-09-24 12:00 |
08:14:54.69 |
+52:57:06.1 |
HIP 40402 |
0.49 |
| 2026-09-25 00:00 |
08:14:59.44 |
+52:57:20.8 |
HIP 40402 |
1.10 |
| 2026-09-25 12:00 |
08:15:04.10 |
+52:57:35.9 |
HIP 40402 |
1.81 |
| 2026-09-26 00:00 |
08:15:08.68 |
+52:57:51.5 |
HIP 40402 |
2.54 |
| 2026-09-26 12:00 |
08:15:13.16 |
+52:58:07.4 |
HIP 40402 |
3.26 |
| 2026-09-27 00:00 |
08:15:17.56 |
+52:58:23.8 |
HIP 40402 |
3.97 |
| 2026-09-27 12:00 |
08:15:21.87 |
+52:58:40.6 |
HIP 40402 |
4.68 |
| 2026-09-28 00:00 |
08:15:26.08 |
+52:58:57.8 |
HIP 40402 |
5.37 |
| 2026-09-28 12:00 |
08:15:30.21 |
+52:59:15.5 |
HIP 40402 |
6.06 |
| 2026-09-29 00:00 |
08:15:34.24 |
+52:59:33.5 |
HIP 40402 |
6.74 |
| 2026-09-29 12:00 |
08:15:38.18 |
+52:59:51.9 |
HIP 40402 |
7.40 |
| 2026-09-30 00:00 |
08:15:42.03 |
+53:00:10.8 |
HIP 40402 |
8.06 |
| 2026-09-30 12:00 |
08:15:45.79 |
+53:00:30.0 |
HIP 40402 |
8.71 |
| 2026-10-01 00:00 |
08:15:49.45 |
+53:00:49.7 |
HIP 40402 |
9.35 |
| 2026-10-01 12:00 |
08:15:53.02 |
+53:01:09.7 |
HIP 40402 |
9.98 |
| 2026-10-02 00:00 |
08:15:56.49 |
+53:01:30.1 |
HIP 40402 |
10.60 |
| 2026-10-02 12:00 |
08:15:59.87 |
+53:01:51.0 |
HIP 40402 |
11.21 |
| 2026-10-03 00:00 |
08:16:03.15 |
+53:02:12.2 |
HIP 40402 |
11.81 |
| 2026-10-03 12:00 |
08:16:06.34 |
+53:02:33.8 |
HIP 40402 |
12.41 |
| 2026-10-04 00:00 |
08:16:09.43 |
+53:02:55.8 |
HIP 40402 |
12.99 |
| 2026-10-04 12:00 |
08:16:12.42 |
+53:03:18.2 |
HIP 40602 |
13.07 |
| 2026-10-05 00:00 |
08:16:15.32 |
+53:03:41.0 |
HIP 40602 |
12.96 |
| 2026-10-05 12:00 |
08:16:18.12 |
+53:04:04.1 |
HIP 40602 |
12.88 |
| 2026-10-06 00:00 |
08:16:20.81 |
+53:04:27.6 |
HIP 40602 |
12.85 |
| 2026-10-06 12:00 |
08:16:23.41 |
+53:04:51.5 |
HIP 40602 |
12.85 |
| 2026-10-07 00:00 |
08:16:25.91 |
+53:05:15.8 |
HIP 40602 |
12.90 |
| 2026-10-07 12:00 |
08:16:28.31 |
+53:05:40.4 |
HIP 40602 |
12.98 |
| 2026-10-08 00:00 |
08:16:30.60 |
+53:06:05.4 |
HIP 40602 |
13.09 |
| 2026-10-08 12:00 |
08:16:32.80 |
+53:06:30.8 |
HIP 40451 |
13.13 |
| 2026-10-09 00:00 |
08:16:34.89 |
+53:06:56.5 |
HIP 40451 |
13.04 |
| 2026-10-09 12:00 |
08:16:36.88 |
+53:07:22.6 |
HIP 40451 |
12.96 |
| 2026-10-10 00:00 |
08:16:38.77 |
+53:07:49.0 |
HIP 40451 |
12.89 |
| 2026-10-10 12:00 |
08:16:40.55 |
+53:08:15.8 |
HIP 40451 |
12.82 |
| 2026-10-11 00:00 |
08:16:42.23 |
+53:08:42.9 |
HIP 40451 |
12.75 |