C/2017 K1 (PANSTARRS)

メタデータ

項目 値
Designation C/2017 K1 (PANSTARRS)
Type C
Perihelion (tp_cal, UTC) 2018-03-14T18:30:37.512000Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:33:33Z
Obs used 138
NEO -
M1 6.900
K1 10.250
PC 0.030
オスキュレーティング軌道要素
項目 値
Epoch (epoch_cal, TDB) 2018-05-01.0000000
e 1.00209402
q (au) 7.285700
a (au) -3479.295246
i (deg) 154.008296
Ω (om, deg) 225.641843
ω (w, deg) 4.202591
M (ma, deg) 0.000227

等級

C/2017 K1 (PANSTARRS) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (8.144 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目 値
H0 8.144
n 6.000
gf 1.000
gb -0.867
k 0.800
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

天体暦

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-09-20 00:00 08:32:51.14 +43:41:10.1 HIP 41917 3.85
2026-09-20 12:00 08:32:54.39 +43:41:31.2 HIP 41917 4.38
2026-09-21 00:00 08:32:57.59 +43:41:52.6 HIP 41917 4.95
2026-09-21 12:00 08:33:00.73 +43:42:14.3 HIP 41917 5.55
2026-09-22 00:00 08:33:03.82 +43:42:36.4 HIP 41917 6.16
2026-09-22 12:00 08:33:06.85 +43:42:58.9 HIP 41917 6.78
2026-09-23 00:00 08:33:09.84 +43:43:21.7 HIP 41917 7.41
2026-09-23 12:00 08:33:12.76 +43:43:44.8 HIP 41917 8.04
2026-09-24 00:00 08:33:15.63 +43:44:08.3 HIP 41917 8.67
2026-09-24 12:00 08:33:18.45 +43:44:32.1 HIP 41917 9.30
2026-09-25 00:00 08:33:21.21 +43:44:56.2 HIP 41917 9.93
2026-09-25 12:00 08:33:23.92 +43:45:20.7 HIP 41917 10.56
2026-09-26 00:00 08:33:26.57 +43:45:45.5 HIP 41917 11.19
2026-09-26 12:00 08:33:29.16 +43:46:10.7 HIP 41917 11.82
2026-09-27 00:00 08:33:31.70 +43:46:36.2 HIP 41917 12.44
2026-09-27 12:00 08:33:34.18 +43:47:02.0 HIP 41917 13.06
2026-09-28 00:00 08:33:36.60 +43:47:28.2 HIP 41917 13.68
2026-09-28 12:00 08:33:38.96 +43:47:54.7 HIP 41917 14.29
2026-09-29 00:00 08:33:41.26 +43:48:21.5 HIP 41917 14.90
2026-09-29 12:00 08:33:43.51 +43:48:48.7 HIP 41917 15.51
2026-09-30 00:00 08:33:45.70 +43:49:16.2 HIP 41917 16.11
2026-09-30 12:00 08:33:47.82 +43:49:44.0 HIP 41917 16.71
2026-10-01 00:00 08:33:49.89 +43:50:12.2 HIP 41917 17.31
2026-10-01 12:00 08:33:51.90 +43:50:40.7 HIP 41917 17.91
2026-10-02 00:00 08:33:53.84 +43:51:09.5 HIP 41917 18.50
2026-10-02 12:00 08:33:55.73 +43:51:38.6 HIP 41917 19.08
2026-10-03 00:00 08:33:57.55 +43:52:08.1 HIP 41917 19.67
2026-10-03 12:00 08:33:59.32 +43:52:37.9 HIP 41917 20.25
2026-10-04 00:00 08:34:01.02 +43:53:08.0 HIP 41917 20.83
2026-10-04 12:00 08:34:02.65 +43:53:38.5 HIP 41917 21.41
2026-10-05 00:00 08:34:04.23 +43:54:09.3 HIP 41917 21.98
2026-10-05 12:00 08:34:05.74 +43:54:40.3 HIP 41917 22.55
2026-10-06 00:00 08:34:07.19 +43:55:11.8 HIP 41917 23.12
2026-10-06 12:00 08:34:08.57 +43:55:43.5 HIP 41917 23.68
2026-10-07 00:00 08:34:09.89 +43:56:15.5 HIP 41917 24.25
2026-10-07 12:00 08:34:11.14 +43:56:47.9 HIP 41917 24.81
2026-10-08 00:00 08:34:12.33 +43:57:20.6 HIP 41917 25.36
2026-10-08 12:00 08:34:13.45 +43:57:53.6 HIP 41917 25.92
2026-10-09 00:00 08:34:14.51 +43:58:26.9 HIP 41917 26.47
2026-10-09 12:00 08:34:15.50 +43:59:00.5 HIP 41917 27.03
2026-10-10 00:00 08:34:16.42 +43:59:34.4 HIP 41917 27.58
2026-10-10 12:00 08:34:17.28 +44:00:08.6 HIP 41917 28.13
2026-10-11 00:00 08:34:18.07 +44:00:43.1 HIP 41917 28.68