メタデータ
| 項目 |
値 |
| Designation |
C/2017 K5 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-03-22T10:59:03.560640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:35Z |
| Obs used |
116 |
| NEO |
- |
| M1 |
6.600 |
| K1 |
8.750 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2019-02-28.0000000 |
| e |
1.00422212 |
| q (au) |
7.680279 |
| a (au) |
-1819.058463 |
| i (deg) |
82.257758 |
| Ω (om, deg) |
102.375800 |
| ω (w, deg) |
171.715759 |
| M (ma, deg) |
-0.004935 |
等級
散乱 + 全体線形
$$
M_a = (-0.133 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
-0.133 |
| n |
6.000 |
| gf |
0.977 |
| gb |
-0.500 |
| k |
1.000 |
| 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 |
| 2017-05-27 |
2020-03-20 |
+13.4876 |
-12.439 |
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) |
| 2026-09-20 00:00 |
04:51:43.79 |
-71:16:27.3 |
HIP 22686 |
18.54 |
| 2026-09-20 12:00 |
04:51:40.64 |
-71:17:52.1 |
HIP 22686 |
17.25 |
| 2026-09-21 00:00 |
04:51:37.29 |
-71:19:16.6 |
HIP 22686 |
15.99 |
| 2026-09-21 12:00 |
04:51:33.73 |
-71:20:40.9 |
HIP 22686 |
14.77 |
| 2026-09-22 00:00 |
04:51:29.97 |
-71:22:04.9 |
HIP 22686 |
13.61 |
| 2026-09-22 12:00 |
04:51:26.01 |
-71:23:28.6 |
HIP 22686 |
12.51 |
| 2026-09-23 00:00 |
04:51:21.84 |
-71:24:52.0 |
HIP 22686 |
11.50 |
| 2026-09-23 12:00 |
04:51:17.47 |
-71:26:15.0 |
HIP 22686 |
10.61 |
| 2026-09-24 00:00 |
04:51:12.89 |
-71:27:37.8 |
HIP 22686 |
9.85 |
| 2026-09-24 12:00 |
04:51:08.11 |
-71:29:00.2 |
HIP 22686 |
9.26 |
| 2026-09-25 00:00 |
04:51:03.12 |
-71:30:22.3 |
HIP 22686 |
8.89 |
| 2026-09-25 12:00 |
04:50:57.93 |
-71:31:44.1 |
HIP 22686 |
8.75 |
| 2026-09-26 00:00 |
04:50:52.54 |
-71:33:05.5 |
HIP 22686 |
8.86 |
| 2026-09-26 12:00 |
04:50:46.94 |
-71:34:26.5 |
HIP 22686 |
9.20 |
| 2026-09-27 00:00 |
04:50:41.14 |
-71:35:47.2 |
HIP 22686 |
9.76 |
| 2026-09-27 12:00 |
04:50:35.13 |
-71:37:07.5 |
HIP 22686 |
10.49 |
| 2026-09-28 00:00 |
04:50:28.92 |
-71:38:27.4 |
HIP 22686 |
11.37 |
| 2026-09-28 12:00 |
04:50:22.50 |
-71:39:47.0 |
HIP 22686 |
12.35 |
| 2026-09-29 00:00 |
04:50:15.88 |
-71:41:06.1 |
HIP 22686 |
13.43 |
| 2026-09-29 12:00 |
04:50:09.05 |
-71:42:24.8 |
HIP 22686 |
14.57 |
| 2026-09-30 00:00 |
04:50:02.02 |
-71:43:43.1 |
HIP 22686 |
15.77 |
| 2026-09-30 12:00 |
04:49:54.79 |
-71:45:00.9 |
HIP 22686 |
17.00 |
| 2026-10-01 00:00 |
04:49:47.35 |
-71:46:18.3 |
HIP 22686 |
18.27 |
| 2026-10-01 12:00 |
04:49:39.71 |
-71:47:35.3 |
HIP 22686 |
19.57 |
| 2026-10-02 00:00 |
04:49:31.86 |
-71:48:51.8 |
HIP 22686 |
20.88 |
| 2026-10-02 12:00 |
04:49:23.81 |
-71:50:07.9 |
HIP 22686 |
22.22 |
| 2026-10-03 00:00 |
04:49:15.55 |
-71:51:23.5 |
HIP 22686 |
23.56 |
| 2026-10-03 12:00 |
04:49:07.09 |
-71:52:38.6 |
HIP 22686 |
24.92 |
| 2026-10-04 00:00 |
04:48:58.43 |
-71:53:53.2 |
HIP 22686 |
26.29 |
| 2026-10-04 12:00 |
04:48:49.56 |
-71:55:07.3 |
HIP 22009 |
26.45 |
| 2026-10-05 00:00 |
04:48:40.49 |
-71:56:20.9 |
HIP 22009 |
25.24 |
| 2026-10-05 12:00 |
04:48:31.22 |
-71:57:34.0 |
HIP 22009 |
24.04 |
| 2026-10-06 00:00 |
04:48:21.75 |
-71:58:46.5 |
HIP 22009 |
22.85 |
| 2026-10-06 12:00 |
04:48:12.07 |
-71:59:58.5 |
HIP 22009 |
21.68 |
| 2026-10-07 00:00 |
04:48:02.19 |
-72:01:10.0 |
HIP 22009 |
20.54 |
| 2026-10-07 12:00 |
04:47:52.12 |
-72:02:20.9 |
HIP 22009 |
19.41 |
| 2026-10-08 00:00 |
04:47:41.84 |
-72:03:31.2 |
HIP 22009 |
18.32 |
| 2026-10-08 12:00 |
04:47:31.36 |
-72:04:41.0 |
HIP 22009 |
17.26 |
| 2026-10-09 00:00 |
04:47:20.68 |
-72:05:50.1 |
HIP 22009 |
16.25 |
| 2026-10-09 12:00 |
04:47:09.81 |
-72:06:58.7 |
HIP 22009 |
15.29 |
| 2026-10-10 00:00 |
04:46:58.74 |
-72:08:06.7 |
HIP 22009 |
14.38 |
| 2026-10-10 12:00 |
04:46:47.47 |
-72:09:14.0 |
HIP 22009 |
13.56 |
| 2026-10-11 00:00 |
04:46:36.00 |
-72:10:20.7 |
HIP 22009 |
12.82 |