Context. Exoplanet properties crucially depend on the parameters of their host stars: more accurate stellar parameters yield more accurate exoplanet characteristics. When the exoplanet host star shows pulsations, asteroseismology can be used for an improved description of the stellar parameters. Aims. We aim to revisit the pulsational properties of β Pic and identify its pulsation modes from normalized amplitudes in five different passbands. We also investigate the potential presence of a magnetic field. Methods. We conducted a frequency analysis using three seasons of BRITE-Constellation observations in the two BRITE filters, the about 620-day-long bRing light curve, and the nearly 8-year-long SMEI photometric time series. We calculated normalized amplitudes using all passbands and including previously published values obtained from ASTEP observations. We investigated the magnetic properties of β Pic using spectropolarimetric observations conducted with the HARPSpol instrument. Using 2D rotating models, we fit the normalized amplitudes and frequencies through Monte Carlo Markov chains. Results. We identify 15 pulsation frequencies in the range from 34 to 55 d~(?1), where two, F13 at 53.6917 d~(?1)and F11 at 50.4921 d~(?1), display clear amplitude variability. We use the normalized amplitudes in up to five passbands to identify the modes as three ??=?1, six ??=?2, and six ??=?3 modes. β Pic is shown to be non-magnetic with an upper limit of the possible undetected dipolar field of 300 Gauss. Conclusions. Multiple fits to the frequencies and normalized amplitudes are obtained, including one with a near equator-on inclination for β Pic, which corresponds to our expectations based on the orbital inclination of β Pic b and the orientation of the circumstellar disk. This solution leads to a rotation rate of 27% of the Keplerian breakup velocity, a radius of 1.497 ± 0.025 R _(⊙), and a mass of 1.797 ± 0.035 M _(⊙). The ～2% errors in radius and mass do not account for uncertainties in the models and a potentially erroneous mode-identification.
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机译：上下文。系外行星的性质至关重要地取决于其宿主恒星的参数：更准确的恒星参数会产生更准确的系外行星特征。当系外行星恒星显示出脉动时，可以使用星震学来更好地描述恒星参数。目的我们旨在重新审视βPic的脉动特性，并从五个不同通带中的归一化幅度确定其脉动模式。我们还研究了磁场的潜在存在。方法。我们在两个BRITE滤镜中使用三个季节的BRITE-Constellation观测进行了频率分析，大约620天的bRing光曲线和将近8年的SMEI光度时间序列。我们使用所有通带并包括从ASTEP观测获得的先前发布的值来计算归一化幅度。我们使用HARPSpol仪器进行的光谱极化观测研究了βPic的磁性。使用2D旋转模型，我们通过蒙特卡洛马尔可夫链拟合归一化的振幅和频率。结果。我们确定了从34到55 d〜（？1）范围内的15个脉动频率，其中两个F13在53.6917 d〜（？1）和F11在50.4921 d〜（？1）时，显示出明显的幅度变化。我们在多达五个通带中使用归一化幅度，以将模式识别为三种Δ= 1，六个Δ= 2和六个Δ= 3模式。 βPic被显示为非磁性的，未检测到的偶极场的上限为300高斯。结论。获得了对频率和归一化幅度的多重拟合，其中包括对βPic具有接近赤道的倾斜度，这与我们根据βPic b的轨道倾斜度和星盘的方向所期望的相对应。该解决方案导致开普勒分解速度的旋转率为27％，半径为1.497±0.025 R _（⊙），质量为1.797±0.035 M _（⊙）。半径和质量的〜2％误差不能说明模型中的不确定性和潜在的错误模式识别。
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