C/2017 U5 (PANSTARRS)

メタデータ

項目
Designation C/2017 U5 (PANSTARRS)
Type C
Perihelion (tp_cal, UTC) 2017-12-19T02:35:57.655680Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:33:37Z
Obs used 92
NEO -
M1 11.800
K1 10.000
PC -
オスキュレーティング軌道要素
項目
Epoch (epoch_cal, TDB) 2017-11-25.0000000
e 0.74456954
q (au) 4.326737
a (au) 16.939001
i (deg) 18.956551
Ω (om, deg) 163.115368
ω (w, deg) 262.150770
M (ma, deg) 359.659169

等級

C/2017 U5 (PANSTARRS) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (14.300 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目
H0 14.300
n 2.000
gf 0.999
gb -1.000
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

天体暦

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-06-01 00:00 13:17:58.91 +04:37:06.8 HIP 64958 13.90
2026-06-01 12:00 13:17:55.66 +04:37:12.2 HIP 64958 14.71
2026-06-02 00:00 13:17:52.47 +04:37:17.2 HIP 64958 15.51
2026-06-02 12:00 13:17:49.32 +04:37:21.8 HIP 64958 16.30
2026-06-03 00:00 13:17:46.22 +04:37:26.0 HIP 64958 17.07
2026-06-03 12:00 13:17:43.17 +04:37:29.8 HIP 64958 17.84
2026-06-04 00:00 13:17:40.17 +04:37:33.2 HIP 64958 18.58
2026-06-04 12:00 13:17:37.21 +04:37:36.2 HIP 64958 19.32
2026-06-05 00:00 13:17:34.31 +04:37:38.7 HIP 64958 20.04
2026-06-05 12:00 13:17:31.46 +04:37:40.9 HIP 64958 20.75
2026-06-06 00:00 13:17:28.66 +04:37:42.7 HIP 64958 21.45
2026-06-06 12:00 13:17:25.91 +04:37:44.0 HIP 64726 21.62
2026-06-07 00:00 13:17:23.21 +04:37:45.0 HIP 64726 20.94
2026-06-07 12:00 13:17:20.56 +04:37:45.5 HIP 64726 20.28
2026-06-08 00:00 13:17:17.96 +04:37:45.6 HIP 64726 19.64
2026-06-08 12:00 13:17:15.41 +04:37:45.4 HIP 64726 19.00
2026-06-09 00:00 13:17:12.91 +04:37:44.7 HIP 64726 18.38
2026-06-09 12:00 13:17:10.47 +04:37:43.6 HIP 64726 17.78
2026-06-10 00:00 13:17:08.08 +04:37:42.1 HIP 64726 17.18
2026-06-10 12:00 13:17:05.74 +04:37:40.2 HIP 64726 16.60
2026-06-11 00:00 13:17:03.45 +04:37:37.9 HIP 64726 16.04
2026-06-11 12:00 13:17:01.22 +04:37:35.2 HIP 64726 15.49
2026-06-12 00:00 13:16:59.04 +04:37:32.2 HIP 64726 14.95
2026-06-12 12:00 13:16:56.91 +04:37:28.6 HIP 64726 14.43
2026-06-13 00:00 13:16:54.83 +04:37:24.7 HIP 64726 13.92
2026-06-13 12:00 13:16:52.81 +04:37:20.4 HIP 64726 13.42
2026-06-14 00:00 13:16:50.84 +04:37:15.7 HIP 64726 12.95
2026-06-14 12:00 13:16:48.93 +04:37:10.6 HIP 64726 12.48
2026-06-15 00:00 13:16:47.07 +04:37:05.1 HIP 64726 12.04
2026-06-15 12:00 13:16:45.26 +04:36:59.2 HIP 64726 11.61
2026-06-16 00:00 13:16:43.51 +04:36:52.9 HIP 64726 11.19
2026-06-16 12:00 13:16:41.82 +04:36:46.3 HIP 64726 10.80
2026-06-17 00:00 13:16:40.17 +04:36:39.2 HIP 64726 10.42
2026-06-17 12:00 13:16:38.59 +04:36:31.7 HIP 64726 10.06
2026-06-18 00:00 13:16:37.06 +04:36:23.8 HIP 64726 9.72
2026-06-18 12:00 13:16:35.58 +04:36:15.6 HIP 64726 9.40
2026-06-19 00:00 13:16:34.16 +04:36:06.9 HIP 64726 9.10
2026-06-19 12:00 13:16:32.79 +04:35:57.9 HIP 64726 8.82
2026-06-20 00:00 13:16:31.48 +04:35:48.5 HIP 64726 8.57
2026-06-20 12:00 13:16:30.22 +04:35:38.7 HIP 64726 8.34
2026-06-21 00:00 13:16:29.02 +04:35:28.5 HIP 64726 8.13
2026-06-21 12:00 13:16:27.87 +04:35:17.9 HIP 64726 7.94
2026-06-22 00:00 13:16:26.78 +04:35:07.0 HIP 64726 7.79