C/2015 K2 (PANSTARRS)

メタデータ

項目 値
Designation C/2015 K2 (PANSTARRS)
Type C
Perihelion (tp_cal, UTC) 2015-06-08T19:07:06.248640Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:33:11Z
Obs used 54
NEO -
M1 20.700
K1 10.000
PC -
オスキュレーティング軌道要素
項目 値
Epoch (epoch_cal, TDB) 2015-05-26.0000000
e 0.99444359
q (au) 1.455282
a (au) 261.910605
i (deg) 29.110346
Ω (om, deg) 223.713883
ω (w, deg) 15.770089
M (ma, deg) 359.996792

等級

C/2015 K2 (PANSTARRS) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (20.000 + 3.100\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目 値
H0 20.000
n 3.100
gf 1.000
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

天体暦

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-09-20 00:00 02:06:41.91 +18:27:04.8 HIP 9824 3.70
2026-09-20 12:00 02:06:38.53 +18:26:49.3 HIP 9824 3.19
2026-09-21 00:00 02:06:35.13 +18:26:33.6 HIP 9824 2.85
2026-09-21 12:00 02:06:31.71 +18:26:17.7 HIP 9824 2.73
2026-09-22 00:00 02:06:28.26 +18:26:01.6 HIP 9824 2.88
2026-09-22 12:00 02:06:24.79 +18:25:45.4 HIP 9824 3.26
2026-09-23 00:00 02:06:21.30 +18:25:29.0 HIP 9824 3.80
2026-09-23 12:00 02:06:17.78 +18:25:12.5 HIP 9824 4.46
2026-09-24 00:00 02:06:14.25 +18:24:55.8 HIP 9824 5.19
2026-09-24 12:00 02:06:10.69 +18:24:38.9 HIP 9824 5.96
2026-09-25 00:00 02:06:07.11 +18:24:21.8 HIP 9824 6.77
2026-09-25 12:00 02:06:03.51 +18:24:04.6 HIP 9824 7.61
2026-09-26 00:00 02:05:59.89 +18:23:47.3 HIP 9824 8.46
2026-09-26 12:00 02:05:56.25 +18:23:29.8 HIP 9824 9.33
2026-09-27 00:00 02:05:52.59 +18:23:12.1 HIP 9824 10.21
2026-09-27 12:00 02:05:48.90 +18:22:54.2 HIP 9824 11.11
2026-09-28 00:00 02:05:45.20 +18:22:36.2 HIP 9824 12.01
2026-09-28 12:00 02:05:41.48 +18:22:18.1 HIP 9824 12.92
2026-09-29 00:00 02:05:37.75 +18:21:59.8 HIP 9824 13.84
2026-09-29 12:00 02:05:33.99 +18:21:41.4 HIP 9824 14.77
2026-09-30 00:00 02:05:30.21 +18:21:22.8 HIP 9824 15.70
2026-09-30 12:00 02:05:26.42 +18:21:04.0 HIP 9824 16.64
2026-10-01 00:00 02:05:22.61 +18:20:45.1 HIP 9824 17.59
2026-10-01 12:00 02:05:18.78 +18:20:26.1 HIP 9824 18.54
2026-10-02 00:00 02:05:14.93 +18:20:06.9 HIP 9824 19.50
2026-10-02 12:00 02:05:11.07 +18:19:47.5 HIP 9824 20.46
2026-10-03 00:00 02:05:07.18 +18:19:28.0 HIP 9627 20.52
2026-10-03 12:00 02:05:03.29 +18:19:08.4 HIP 9627 19.55
2026-10-04 00:00 02:04:59.38 +18:18:48.6 HIP 9627 18.58
2026-10-04 12:00 02:04:55.45 +18:18:28.7 HIP 9627 17.60
2026-10-05 00:00 02:04:51.50 +18:18:08.7 HIP 9627 16.62
2026-10-05 12:00 02:04:47.55 +18:17:48.5 HIP 9627 15.63
2026-10-06 00:00 02:04:43.57 +18:17:28.2 HIP 9627 14.65
2026-10-06 12:00 02:04:39.58 +18:17:07.7 HIP 9627 13.66
2026-10-07 00:00 02:04:35.58 +18:16:47.1 HIP 9627 12.67
2026-10-07 12:00 02:04:31.57 +18:16:26.4 HIP 9627 11.69
2026-10-08 00:00 02:04:27.54 +18:16:05.6 HIP 9627 10.70
2026-10-08 12:00 02:04:23.50 +18:15:44.6 HIP 9627 9.72
2026-10-09 00:00 02:04:19.45 +18:15:23.5 HIP 9627 8.75
2026-10-09 12:00 02:04:15.38 +18:15:02.3 HIP 9627 7.78
2026-10-10 00:00 02:04:11.30 +18:14:40.9 HIP 9627 6.83
2026-10-10 12:00 02:04:07.21 +18:14:19.4 HIP 9627 5.91
2026-10-11 00:00 02:04:03.11 +18:13:57.9 HIP 9627 5.02