Accurate p-mode measurements of the G0V metal-rich CoRoT target HD 52265
Accurate p-mode measurements of the G0V metal-rich CoRoT target HD 52265
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DOI：
10.1051/0004-6361/201116547
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发表时间：
2011-05
影响因子：
6.5
通讯作者：
J. Ballot;J. Ballot;L. Gizon;R. Samadi;G. Vauclair;G. Vauclair;O. Benomar;O. Benomar;H. Bruntt;B. Mosser;T. Stahn;G. Verner;G. Verner;T. Campante;T. Campante;R. A. García;S. Mathur;D. Salabert;D. Salabert;D. Salabert;P. Gaulme;C. Régulo;C. Régulo;I. Roxburgh;T. Appourchaux;F. Baudin;C. Català;W. Chaplin;S. Deheuvels;Eric Michel;M. Bazot;O. Creevey;O. Creevey;N. Dolez;N. Dolez;Y. Elsworth;K. Sato;S. Vauclair;S. Vauclair;M. Auvergne;A. Baglin
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文献类型：
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作者：
J. Ballot;J. Ballot;L. Gizon;R. Samadi;G. Vauclair;G. Vauclair;O. Benomar;O. Benomar;H. Bruntt;B. Mosser;T. Stahn;G. Verner;G. Verner;T. Campante;T. Campante;R. A. García;S. Mathur;D. Salabert;D. Salabert;D. Salabert;P. Gaulme;C. Régulo;C. Régulo;I. Roxburgh;T. Appourchaux;F. Baudin;C. Català;W. Chaplin;S. Deheuvels;Eric Michel;M. Bazot;O. Creevey;O. Creevey;N. Dolez;N. Dolez;Y. Elsworth;K. Sato;S. Vauclair;S. Vauclair;M. Auvergne;A. Baglin
语境。 HD 52265恒星是一颗G0V富含金属的系外行星主星，于2008年11月至2009年3月在CoRoT太空望远镜的地震学领域观测到。卫星收集了这颗恒星117天的高精度光度数据，显示它呈现出类太阳振荡。同一时期的纳尔瓦尔摄谱仪也在光谱中观察到了 HD 52265。目标。我们使用光谱和地震数据来表征 HD 52265。方法。 HD 52265 的基本恒星参数是用半自动软件 VWA 导出的，并且通过将合成剖面拟合到观测光谱中的孤立线来估计预计的旋转速度。观察到的 p 模式的参数是通过最大似然估计确定的。我们对 l = 0 到 2 度的振荡频谱进行了大约十个径向阶的全局拟合。我们还推导了颗粒化的特性，并分析了光球磁活动引起的旋转特征。结果。已获得基本参数的精确测定：Teff = 6100 ± 60 K，log g = 4.35 ± 0.09，[M/H] = 0.19 ± 0.05，以及 v sini = 3.6 +0.3 −1.0 km s −1 。我们测量了平均旋转周期 P rot = 12.3 ± 0.15 天，并找到了差异旋转的特征。据报告，31 种模式的频率范围为 1500–2550 μHz。大间隔在平均值 Δν = 98.3 ± 0.1 μHz 附近表现出明显的调制。模式宽度随频率沿 S 形变化，在 1800 μHz 附近有明显的局部最大值。我们推断这些模式的寿命在 0.5 到 3 天之间。最后，我们发现径向模式的最大辐射热振幅约为 3.96 ± 0.24 ppm。
Context. The star HD 52265 is a G0V metal-rich exoplanet-host star observed in the seismology field of the CoRoT space telescope from November 2008 to March 2009. The satellite collected 117 days of high-precision photometric data on this star, showing that it presents solar-like oscillations. HD 52265 was also observed in spectroscopy with the Narval spectrograph at the same epoch. Aims. We characterise HD 52265 using both spectroscopic and seismic data. Methods. The fundamental stellar parameters of HD 52265 were derived with the semi-automatic software VWA, and the projected rotational velocity was estimated by fitting synthetic profiles to isolated lines in the observed spectrum. The parameters of the observed p modes were determined with a maximum-likelihood estimation. We performed a global fit of the oscillation spectrum, over about ten radial orders, for degrees l = 0 to 2. We also derived the properties of the granulation, and analysed a signature of the rotation induced by the photospheric magnetic activity. Results. Precise determinations of fundamental parameters have been obtained: Teff = 6100 ± 60 K, log g = 4.35 ± 0.09, [M/H] = 0.19 ± 0.05, as well as v sini = 3.6 +0.3 −1.0 km s −1 . We have measured a mean rotation period P rot = 12.3 ± 0.15 days, and find a signature of differential rotation. The frequencies of 31 modes are reported in the range 1500–2550 μHz. The large separation exhibits a clear modulation around the mean value Δν = 98.3 ± 0.1 μHz. Mode widths vary with frequency along an S-shape with a clear local maximum around 1800 μHz. We deduce lifetimes ranging between 0.5 and 3 days for these modes. Finally, we find a maximal bolometric amplitude of about 3.96 ± 0.24 ppm for radial modes.