C/2012 S4 (PANSTARRS)

メタデータ

項目
Designation C/2012 S4 (PANSTARRS)
Type C
Perihelion (tp_cal, UTC) 2013-06-28T00:33:42.019200Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:32:22Z
Obs used 924
NEO -
M1 9.400
K1 8.750
PC 0.030
オスキュレーティング軌道要素
項目
Epoch (epoch_cal, TDB) 2013-04-24.0000000
e 0.99998199
q (au) 4.348728
a (au) 241497.706412
i (deg) 126.541334
Ω (om, deg) 173.103524
ω (w, deg) 163.615485
M (ma, deg) 359.999999

等級

C/2012 S4 (PANSTARRS) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (7.720 + 4.989\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目
H0 7.720
n 4.989
gf 0.997
gb -0.512
k 0.800
δ90 9.110
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)
2026-05-12 00:00 12:57:21.61 -59:14:55.0 HIP 63275 11.07
2026-05-12 12:00 12:57:14.72 -59:14:05.1 HIP 63275 10.79
2026-05-13 00:00 12:57:07.88 -59:13:14.9 HIP 63275 10.64
2026-05-13 12:00 12:57:01.09 -59:12:24.4 HIP 63275 10.62
2026-05-14 00:00 12:56:54.34 -59:11:33.7 HIP 63275 10.72
2026-05-14 12:00 12:56:47.64 -59:10:42.6 HIP 63275 10.96
2026-05-15 00:00 12:56:41.00 -59:09:51.2 HIP 63275 11.31
2026-05-15 12:00 12:56:34.40 -59:08:59.6 HIP 63275 11.77
2026-05-16 00:00 12:56:27.85 -59:08:07.6 HIP 63275 12.32
2026-05-16 12:00 12:56:21.35 -59:07:15.4 HIP 63049 11.20
2026-05-17 00:00 12:56:14.90 -59:06:22.9 HIP 63049 10.03
2026-05-17 12:00 12:56:08.50 -59:05:30.2 HIP 63049 8.87
2026-05-18 00:00 12:56:02.16 -59:04:37.2 HIP 63049 7.74
2026-05-18 12:00 12:55:55.86 -59:03:43.9 HIP 63049 6.63
2026-05-19 00:00 12:55:49.62 -59:02:50.4 HIP 63049 5.57
2026-05-19 12:00 12:55:43.44 -59:01:56.7 HIP 63049 4.57
2026-05-20 00:00 12:55:37.30 -59:01:02.7 HIP 63049 3.71
2026-05-20 12:00 12:55:31.22 -59:00:08.4 HIP 63049 3.09
2026-05-21 00:00 12:55:25.19 -58:59:14.0 HIP 63049 2.87
2026-05-21 12:00 12:55:19.22 -58:58:19.3 HIP 63049 3.13
2026-05-22 00:00 12:55:13.30 -58:57:24.4 HIP 63049 3.77
2026-05-22 12:00 12:55:07.44 -58:56:29.2 HIP 63049 4.64
2026-05-23 00:00 12:55:01.63 -58:55:33.9 HIP 63049 5.63
2026-05-23 12:00 12:54:55.88 -58:54:38.3 HIP 63049 6.69
2026-05-24 00:00 12:54:50.19 -58:53:42.5 HIP 63049 7.78
2026-05-24 12:00 12:54:44.55 -58:52:46.5 HIP 63049 8.90
2026-05-25 00:00 12:54:38.96 -58:51:50.4 HIP 63049 10.03
2026-05-25 12:00 12:54:33.44 -58:50:54.0 HIP 63049 11.18
2026-05-26 00:00 12:54:27.97 -58:49:57.5 HIP 63049 12.33
2026-05-26 12:00 12:54:22.56 -58:49:00.7 HIP 63049 13.48
2026-05-27 00:00 12:54:17.20 -58:48:03.8 HIP 63049 14.64
2026-05-27 12:00 12:54:11.91 -58:47:06.7 HIP 62823 14.04
2026-05-28 00:00 12:54:06.67 -58:46:09.5 HIP 62823 13.24
2026-05-28 12:00 12:54:01.49 -58:45:12.0 HIP 62823 12.51
2026-05-29 00:00 12:53:56.37 -58:44:14.4 HIP 62823 11.86
2026-05-29 12:00 12:53:51.31 -58:43:16.7 HIP 62823 11.30
2026-05-30 00:00 12:53:46.31 -58:42:18.8 HIP 62823 10.84
2026-05-30 12:00 12:53:41.36 -58:41:20.7 HIP 62823 10.49
2026-05-31 00:00 12:53:36.48 -58:40:22.5 HIP 62823 10.28
2026-05-31 12:00 12:53:31.66 -58:39:24.2 HIP 62823 10.20
2026-06-01 00:00 12:53:26.89 -58:38:25.7 HIP 62823 10.26
2026-06-01 12:00 12:53:22.19 -58:37:27.1 HIP 62823 10.45
2026-06-02 00:00 12:53:17.54 -58:36:28.4 HIP 62823 10.77