论文标题
二进制系统的后续观察$γ$ CEP
Follow-up observations of the binary system $γ$ Cep
论文作者
论文摘要
我们介绍了外部活动的新成像和光谱观察结果$γ$ CEP A及其低质量恒星伴侣$γ$ CEP B的新成像和观察结果。我们使用Astralux/Caha遵循伴侣在其小学周围的轨道运动遵循其小学的轨道运动，其辐射速度与恒星的光谱速度确定了恒星的光谱，并用Spectrograph flechas jena jena jena jena jena jena jena jena jena jena。我们在所有Astralux图像中都测量了$γ$ CEP B相对于其主要的主体测量值，并确定了其明显的SDSS I频段光度法，为此我们获得了I'= 9.84 $ \ pm $ 0.17 mag。使用恒星进化模型和外部宿主星的Gaia视差，我们得出了$γ$ CEP B的质量为0.39 $ \ pm $ 0.03 m $ $ {_ \ odot} $。这与文献中给出的同伴的质量非常吻合。在我们的Astralux图像中达到的检测极限，我们探索了$γ$ CEP二进制系统中潜在附加伴侣的检测空间。在背景有限区域中，可以在$γ$ cep A左右检测到5''（或69 au）的角度分离（或69 au）的同伴。这允许检测Proj的同伴。分离最多155 au。但是，除了$γ$ CEP B外，在系外行星寄主之星周围没有其他伴侣。我们重新确定了$γ$ CEP二进制系统的轨道解决方案，新的Astralux天文统计$γ$ CEP B和$γ$ CEP A的额外径向速度，从我们的恒星的Flechas Spectroscoppoys获得，结合了文献中的天体和辐射速度数据。确定的轨道元素用于得出系统参数，并计算出有趣的系外行星宿主二进制二进制恒星系统的特定未来埃菲米尔。
We present new imaging and spectroscopic observations of the exoplanet host star $γ$ Cep A, and of its low-mass stellar companion $γ$ Cep B. We used AstraLux/CAHA to follow the orbital motion of the companion around its primary, whose radial velocity was determined with spectra of the star, taken with the spectrograph FLECHAS at the University Observatory Jena. We measured the astrometry of $γ$ Cep B relative to its primary in all AstraLux images and determined its apparent SDSS i'-band photometry, for which we obtained i'=9.84$\pm$0.17 mag. Using stellar evolutionary models and the Gaia parallax of the exoplanet host star, we derived the mass of $γ$ Cep B to be 0.39$\pm$0.03 M${_\odot}$. This is in good agreement with the mass of the companion, derived from its NIR photometry, given in the literature. With the detection limit, reached in our AstraLux images, we explored the detection space of potential additional companions in the $γ$ Cep binary system. In the background limited region at angular separations larger then 5 '' (or 69 au of proj. separation) companions down to 0.11 M$_\odot$ are detectable around $γ$ Cep A. The radial FoV, fully covered in our AstraLux images, exhibits a radius of 11.2 ''. This allows the detection of companions with proj. separations up to 155 au. However, except for $γ$ Cep B no additional companions could be imaged around the exoplanet host star. We redetermined the orbital solution of the $γ$ Cep binary system with the new AstraLux astrometry of $γ$ Cep B and the additional radial velocities of $γ$ Cep A, obtained from our FLECHAS spectroscopy of the star, combined with astrometric and radial velocity data from the literature. The determined orbital elements were used to derive the system parameters and to calculate specific future ephemeris for this intriguing exoplanet host binary star system.
