C/2005 S4 (McNaught)

メタデータ

項目
Designation C/2005 S4 (McNaught)
Type C
Perihelion (tp_cal, UTC) 2007-07-18T15:31:21.316800Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:30:53Z
Obs used 580
NEO -
M1 9.900
K1 5.500
PC -
オスキュレーティング軌道要素
項目
Epoch (epoch_cal, TDB) 2007-06-06.0000000
e 0.99897119
q (au) 5.850108
a (au) 5686.269098
i (deg) 107.958958
Ω (om, deg) 318.290291
ω (w, deg) 31.453945
M (ma, deg) 359.999902

等級

C/2005 S4 (McNaught) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (6.966 + 3.745\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目
H0 6.966
n 3.745
gf 0.995
gb -0.897
k 0.999
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

残差 (区間線形)

$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$

開始日 (UTC) 終了日 (UTC) a b
2005-07-27 2007-07-16 -1.0253 +0.679
2007-07-19 2008-10-06 +18.7523 -14.647
2008-10-06 2009-07-23 +4.6293 -3.301

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)
2026-06-01 00:00 10:00:22.70 +28:59:31.2 HIP 49103 17.42
2026-06-01 12:00 10:00:23.22 +28:59:09.8 HIP 49103 17.09
2026-06-02 00:00 10:00:23.77 +28:58:48.4 HIP 49103 16.75
2026-06-02 12:00 10:00:24.35 +28:58:26.8 HIP 49103 16.41
2026-06-03 00:00 10:00:24.96 +28:58:05.2 HIP 49103 16.06
2026-06-03 12:00 10:00:25.60 +28:57:43.4 HIP 49103 15.71
2026-06-04 00:00 10:00:26.27 +28:57:21.6 HIP 49103 15.36
2026-06-04 12:00 10:00:26.96 +28:56:59.6 HIP 49103 15.00
2026-06-05 00:00 10:00:27.69 +28:56:37.6 HIP 49103 14.64
2026-06-05 12:00 10:00:28.44 +28:56:15.5 HIP 49103 14.28
2026-06-06 00:00 10:00:29.22 +28:55:53.3 HIP 49103 13.91
2026-06-06 12:00 10:00:30.03 +28:55:31.0 HIP 49103 13.54
2026-06-07 00:00 10:00:30.86 +28:55:08.7 HIP 49103 13.17
2026-06-07 12:00 10:00:31.73 +28:54:46.2 HIP 49103 12.79
2026-06-08 00:00 10:00:32.62 +28:54:23.7 HIP 49103 12.41
2026-06-08 12:00 10:00:33.54 +28:54:01.1 HIP 49103 12.02
2026-06-09 00:00 10:00:34.49 +28:53:38.4 HIP 49103 11.64
2026-06-09 12:00 10:00:35.46 +28:53:15.6 HIP 49103 11.25
2026-06-10 00:00 10:00:36.47 +28:52:52.8 HIP 49103 10.86
2026-06-10 12:00 10:00:37.50 +28:52:29.8 HIP 49103 10.46
2026-06-11 00:00 10:00:38.55 +28:52:06.8 HIP 49103 10.07
2026-06-11 12:00 10:00:39.64 +28:51:43.8 HIP 49103 9.67
2026-06-12 00:00 10:00:40.75 +28:51:20.6 HIP 49103 9.28
2026-06-12 12:00 10:00:41.89 +28:50:57.4 HIP 49103 8.88
2026-06-13 00:00 10:00:43.06 +28:50:34.1 HIP 49103 8.48
2026-06-13 12:00 10:00:44.25 +28:50:10.7 HIP 49103 8.09
2026-06-14 00:00 10:00:45.47 +28:49:47.3 HIP 49103 7.70
2026-06-14 12:00 10:00:46.71 +28:49:23.8 HIP 49103 7.31
2026-06-15 00:00 10:00:47.99 +28:49:00.3 HIP 49103 6.92
2026-06-15 12:00 10:00:49.29 +28:48:36.6 HIP 49103 6.55
2026-06-16 00:00 10:00:50.61 +28:48:13.0 HIP 49103 6.18
2026-06-16 12:00 10:00:51.96 +28:47:49.2 HIP 49103 5.83
2026-06-17 00:00 10:00:53.34 +28:47:25.4 HIP 49103 5.49
2026-06-17 12:00 10:00:54.74 +28:47:01.6 HIP 49103 5.17
2026-06-18 00:00 10:00:56.17 +28:46:37.7 HIP 49103 4.88
2026-06-18 12:00 10:00:57.62 +28:46:13.7 HIP 49103 4.61
2026-06-19 00:00 10:00:59.10 +28:45:49.7 HIP 49103 4.39
2026-06-19 12:00 10:01:00.60 +28:45:25.6 HIP 49103 4.21
2026-06-20 00:00 10:01:02.13 +28:45:01.5 HIP 49103 4.09
2026-06-20 12:00 10:01:03.68 +28:44:37.4 HIP 49103 4.03
2026-06-21 00:00 10:01:05.26 +28:44:13.2 HIP 49103 4.04
2026-06-21 12:00 10:01:06.86 +28:43:48.9 HIP 49103 4.11
2026-06-22 00:00 10:01:08.49 +28:43:24.6 HIP 49103 4.24