论文标题
T Tauri三重系统中的轨道运动，可变性和质量
Orbital Motion, Variability, and Masses in the T Tauri Triple System
论文作者
论文摘要
我们介绍了2015 - 2019年在Keck和Gemini天文台获得的T Tauri三重系统的自适应光学成像。我们相对于Sa的T Tau SB的轨道运动，并模拟其质量中心相对于T Tau N的星体运动。使用Gaia测得的距离，我们得出了M_SA的动力学质量= 2.05 +/- 0.14 msun和M_SB = 0.43 +/- 0.06 MSUN。通过持续的观察，可以提高质量的精度，这些观察结果可以通过完整的轨道时期绘制运动；这一点尤其重要，因为该系统在2023年接近Periastron通道。根据已发表的特性和最近的进化轨道，我们估计T tau n的质量约为2 msun，这表明T tau n与T Tau Sa相似。窄带红外光度法表明，在2017年末至2019年初之间，T tau N保持相对恒定，平均值为k = 5.54 +/- 0.07 mag。自2015年以来，使用t tau n来校准相对通量测量值，我们发现，在K频段的时间尺度上，t tau sa在k波段中的7.0至8.8 mag之间变化，而t tau sb在k频段中从8.5降低到11.1。在T tau的二元期的27年轨道时期，相对于T tau N.
We present results from adaptive optics imaging of the T Tauri triple system obtained at the Keck and Gemini Observatories in 2015-2019. We fit the orbital motion of T Tau Sb relative to Sa and model the astrometric motion of their center of mass relative to T Tau N. Using the distance measured by Gaia, we derived dynamical masses of M_Sa = 2.05 +/- 0.14 Msun and M_Sb = 0.43 +/- 0.06 Msun. The precision in the masses is expected to improve with continued observations that map the motion through a complete orbital period; this is particularly important as the system approaches periastron passage in 2023. Based on published properties and recent evolutionary tracks, we estimate a mass of ~ 2 Msun for T Tau N, suggesting that T Tau N is similar in mass to T Tau Sa. Narrow-band infrared photometry shows that T Tau N remained relatively constant between late 2017 and early 2019 with an average value of K = 5.54 +/- 0.07 mag. Using T Tau N to calibrate relative flux measurements since 2015, we found that T Tau Sa varied dramatically between 7.0 to 8.8 mag in the K-band over timescales of a few months, while T Tau Sb faded steadily from 8.5 to 11.1 mag in the K-band. Over the 27 year orbital period of the T Tau S binary, both components have shown 3-4 magnitudes of variability in the K-band, relative to T Tau N.
