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) |
| 2026-07-29 00:00 |
04:40:01.78 |
-68:48:47.7 |
HIP 21599 |
9.81 |
| 2026-07-29 12:00 |
04:40:16.49 |
-68:49:57.2 |
HIP 21599 |
11.21 |
| 2026-07-30 00:00 |
04:40:31.08 |
-68:51:07.1 |
HIP 21599 |
12.68 |
| 2026-07-30 12:00 |
04:40:45.54 |
-68:52:17.5 |
HIP 21599 |
14.21 |
| 2026-07-31 00:00 |
04:40:59.88 |
-68:53:28.3 |
HIP 21901 |
14.16 |
| 2026-07-31 12:00 |
04:41:14.09 |
-68:54:39.6 |
HIP 21901 |
12.44 |
| 2026-08-01 00:00 |
04:41:28.18 |
-68:55:51.4 |
HIP 21901 |
10.73 |
| 2026-08-01 12:00 |
04:41:42.14 |
-68:57:03.6 |
HIP 21901 |
9.04 |
| 2026-08-02 00:00 |
04:41:55.98 |
-68:58:16.2 |
HIP 21901 |
7.36 |
| 2026-08-02 12:00 |
04:42:09.68 |
-68:59:29.3 |
HIP 21901 |
5.72 |
| 2026-08-03 00:00 |
04:42:23.26 |
-69:00:42.8 |
HIP 21901 |
4.15 |
| 2026-08-03 12:00 |
04:42:36.70 |
-69:01:56.7 |
HIP 21901 |
2.75 |
| 2026-08-04 00:00 |
04:42:50.02 |
-69:03:11.1 |
HIP 21901 |
1.96 |
| 2026-08-04 12:00 |
04:43:03.20 |
-69:04:25.9 |
HIP 21901 |
2.44 |
| 2026-08-05 00:00 |
04:43:16.25 |
-69:05:41.1 |
HIP 21901 |
3.72 |
| 2026-08-05 12:00 |
04:43:29.16 |
-69:06:56.7 |
HIP 21901 |
5.24 |
| 2026-08-06 00:00 |
04:43:41.94 |
-69:08:12.7 |
HIP 21901 |
6.84 |
| 2026-08-06 12:00 |
04:43:54.58 |
-69:09:29.1 |
HIP 21901 |
8.48 |
| 2026-08-07 00:00 |
04:44:07.09 |
-69:10:45.9 |
HIP 21901 |
10.13 |
| 2026-08-07 12:00 |
04:44:19.46 |
-69:12:03.1 |
HIP 21901 |
11.78 |
| 2026-08-08 00:00 |
04:44:31.68 |
-69:13:20.7 |
HIP 21901 |
13.44 |
| 2026-08-08 12:00 |
04:44:43.77 |
-69:14:38.7 |
HIP 21901 |
15.10 |
| 2026-08-09 00:00 |
04:44:55.72 |
-69:15:57.0 |
HIP 21901 |
16.75 |
| 2026-08-09 12:00 |
04:45:07.52 |
-69:17:15.7 |
HIP 21901 |
18.41 |
| 2026-08-10 00:00 |
04:45:19.18 |
-69:18:34.8 |
HIP 21901 |
20.06 |
| 2026-08-10 12:00 |
04:45:30.69 |
-69:19:54.2 |
HIP 22392 |
20.89 |
| 2026-08-11 00:00 |
04:45:42.06 |
-69:21:14.0 |
HIP 22392 |
19.49 |
| 2026-08-11 12:00 |
04:45:53.28 |
-69:22:34.1 |
HIP 22392 |
18.15 |
| 2026-08-12 00:00 |
04:46:04.36 |
-69:23:54.5 |
HIP 22392 |
16.88 |
| 2026-08-12 12:00 |
04:46:15.28 |
-69:25:15.3 |
HIP 22392 |
15.70 |
| 2026-08-13 00:00 |
04:46:26.05 |
-69:26:36.4 |
HIP 22392 |
14.62 |
| 2026-08-13 12:00 |
04:46:36.68 |
-69:27:57.8 |
HIP 22392 |
13.67 |
| 2026-08-14 00:00 |
04:46:47.15 |
-69:29:19.6 |
HIP 22392 |
12.88 |
| 2026-08-14 12:00 |
04:46:57.47 |
-69:30:41.6 |
HIP 22392 |
12.27 |
| 2026-08-15 00:00 |
04:47:07.64 |
-69:32:04.0 |
HIP 22392 |
11.88 |
| 2026-08-15 12:00 |
04:47:17.65 |
-69:33:26.6 |
HIP 22392 |
11.73 |
| 2026-08-16 00:00 |
04:47:27.50 |
-69:34:49.5 |
HIP 22392 |
11.81 |
| 2026-08-16 12:00 |
04:47:37.20 |
-69:36:12.7 |
HIP 22392 |
12.13 |
| 2026-08-17 00:00 |
04:47:46.75 |
-69:37:36.2 |
HIP 22392 |
12.66 |
| 2026-08-17 12:00 |
04:47:56.13 |
-69:38:59.9 |
HIP 22392 |
13.38 |
| 2026-08-18 00:00 |
04:48:05.36 |
-69:40:23.9 |
HIP 22392 |
14.26 |
| 2026-08-18 12:00 |
04:48:14.42 |
-69:41:48.1 |
HIP 22392 |
15.27 |
| 2026-08-19 00:00 |
04:48:23.33 |
-69:43:12.6 |
HIP 22392 |
16.39 |