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 |
0.978 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
9.999 |
| 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) |
| 2026-03-26 00:00 |
03:09:52.38 |
-69:53:32.1 |
HIP 15120 |
27.10 |
| 2026-03-26 12:00 |
03:10:12.97 |
-69:51:48.1 |
HIP 15120 |
25.01 |
| 2026-03-27 00:00 |
03:10:33.64 |
-69:50:04.7 |
HIP 15120 |
22.98 |
| 2026-03-27 12:00 |
03:10:54.39 |
-69:48:21.8 |
HIP 15120 |
21.04 |
| 2026-03-28 00:00 |
03:11:15.20 |
-69:46:39.6 |
HIP 15120 |
19.21 |
| 2026-03-28 12:00 |
03:11:36.09 |
-69:44:57.9 |
HIP 15120 |
17.53 |
| 2026-03-29 00:00 |
03:11:57.04 |
-69:43:16.9 |
HIP 15120 |
16.04 |
| 2026-03-29 12:00 |
03:12:18.07 |
-69:41:36.4 |
HIP 15120 |
14.81 |
| 2026-03-30 00:00 |
03:12:39.17 |
-69:39:56.6 |
HIP 15120 |
13.89 |
| 2026-03-30 12:00 |
03:13:00.33 |
-69:38:17.3 |
HIP 15120 |
13.36 |
| 2026-03-31 00:00 |
03:13:21.56 |
-69:36:38.7 |
HIP 15120 |
13.26 |
| 2026-03-31 12:00 |
03:13:42.85 |
-69:35:00.7 |
HIP 15120 |
13.60 |
| 2026-04-01 00:00 |
03:14:04.21 |
-69:33:23.3 |
HIP 15120 |
14.34 |
| 2026-04-01 12:00 |
03:14:25.64 |
-69:31:46.5 |
HIP 15120 |
15.44 |
| 2026-04-02 00:00 |
03:14:47.13 |
-69:30:10.3 |
HIP 15120 |
16.82 |
| 2026-04-02 12:00 |
03:15:08.68 |
-69:28:34.7 |
HIP 15120 |
18.41 |
| 2026-04-03 00:00 |
03:15:30.29 |
-69:26:59.8 |
HIP 15120 |
20.17 |
| 2026-04-03 12:00 |
03:15:51.96 |
-69:25:25.5 |
HIP 15120 |
22.06 |
| 2026-04-04 00:00 |
03:16:13.69 |
-69:23:51.9 |
HIP 15120 |
24.04 |
| 2026-04-04 12:00 |
03:16:35.48 |
-69:22:18.8 |
HIP 15120 |
26.09 |
| 2026-04-05 00:00 |
03:16:57.33 |
-69:20:46.4 |
HIP 15120 |
28.20 |
| 2026-04-05 12:00 |
03:17:19.24 |
-69:19:14.7 |
HIP 15730 |
28.26 |
| 2026-04-06 00:00 |
03:17:41.20 |
-69:17:43.6 |
HIP 15730 |
26.35 |
| 2026-04-06 12:00 |
03:18:03.23 |
-69:16:13.1 |
HIP 15730 |
24.53 |
| 2026-04-07 00:00 |
03:18:25.30 |
-69:14:43.3 |
HIP 15730 |
22.82 |
| 2026-04-07 12:00 |
03:18:47.43 |
-69:13:14.1 |
HIP 15730 |
21.24 |
| 2026-04-08 00:00 |
03:19:09.61 |
-69:11:45.6 |
HIP 15730 |
19.83 |
| 2026-04-08 12:00 |
03:19:31.85 |
-69:10:17.7 |
HIP 15730 |
18.63 |
| 2026-04-09 00:00 |
03:19:54.14 |
-69:08:50.5 |
HIP 15730 |
17.67 |
| 2026-04-09 12:00 |
03:20:16.48 |
-69:07:24.0 |
HIP 15730 |
17.00 |
| 2026-04-10 00:00 |
03:20:38.87 |
-69:05:58.1 |
HIP 15730 |
16.66 |
| 2026-04-10 12:00 |
03:21:01.31 |
-69:04:32.9 |
HIP 15730 |
16.65 |
| 2026-04-11 00:00 |
03:21:23.80 |
-69:03:08.3 |
HIP 15730 |
16.99 |
| 2026-04-11 12:00 |
03:21:46.33 |
-69:01:44.5 |
HIP 15730 |
17.64 |
| 2026-04-12 00:00 |
03:22:08.92 |
-69:00:21.3 |
HIP 15730 |
18.59 |
| 2026-04-12 12:00 |
03:22:31.55 |
-68:58:58.8 |
HIP 15730 |
19.78 |
| 2026-04-13 00:00 |
03:22:54.22 |
-68:57:37.0 |
HIP 15730 |
21.17 |
| 2026-04-13 12:00 |
03:23:16.95 |
-68:56:15.8 |
HIP 15730 |
22.73 |
| 2026-04-14 00:00 |
03:23:39.71 |
-68:54:55.4 |
HIP 15730 |
24.43 |
| 2026-04-14 12:00 |
03:24:02.52 |
-68:53:35.6 |
HIP 15730 |
26.23 |
| 2026-04-15 00:00 |
03:24:25.37 |
-68:52:16.6 |
HIP 15681 |
27.13 |
| 2026-04-15 12:00 |
03:24:48.26 |
-68:50:58.2 |
HIP 15681 |
27.11 |
| 2026-04-16 00:00 |
03:25:11.19 |
-68:49:40.6 |
HIP 15681 |
27.32 |