论文标题
朝向预定序列二进制系统V928 TAU的不对称日食
An Asymmetric Eclipse Seen Towards the Pre-Main Sequence Binary System V928 Tau
论文作者
论文摘要
K2对弱衬有TAuri二进制V928 tau a+B的观察结果显示了一个单一的,不对称的日食的检测,这可能是由于先前未知的近代伴侣黯然失色的二进制组成部分,其轨道周期$> $ 66。在大约9个小时的时间间隔内,二进制DIM的一个组成部分约为60%,大约5小时后恢复其正常亮度。通过对日食形状进行建模,我们发现证据表明,黯然失色的伴侣可能被磁盘或巨大的环系统包围。模型的磁盘的半径为$ 0.9923 \,\ pm \,0.0005 \,r _*$,倾向于$ 56.78 \,\ pm \,0.03^\ circ $,倾斜度为$ 41.22 $ -0.2506 \,\ pm \,0.0002 \,r _*$,不透明度为1.00。横向速度也必须以$ 6.637 \,\ pm \,0.002 \,r _*\,\ mathrm {day}^{ - 1} $移动,取决于它是绕v928 tau a还是B,大约对应于73.53或69.26 $ \ km s}^{ - 1} $。基于地面的档案数据的搜索显示了其他调度事件,其中一些暗示了周期性,但与K2观察到的Eclipse没有明确的时期。我们提出了一个新的天文标准,该时期用于进一步完善二进制的轨道,呈现了67年的新下限,并在可能的轨道时期的轨道时期受到限制。二进制的二进制也与下部质量CFHT-BD-TAU 7分开18英寸($ \ sim $ 2250 au),这可能与V928 tau a+b。我们还提供了新的高分散光学光谱,我们用来表征未解决的恒星二进制。
K2 observations of the weak-lined T Tauri binary V928 Tau A+B show the detection of a single, asymmetric eclipse which may be due to a previously unknown substellar companion eclipsing one component of the binary with an orbital period $>$ 66 days. Over an interval of about 9 hours, one component of the binary dims by around 60%, returning to its normal brightness about 5 hours later. From modeling of the eclipse shape we find evidence that the eclipsing companion may be surrounded by a disk or a vast ring system. The modeled disk has a radius of $0.9923\,\pm\,0.0005\,R_*$, with an inclination of $56.78\,\pm\, 0.03^\circ$, a tilt of $41.22\,\pm\,0.05^\circ$, an impact parameter of $-0.2506\,\pm\,0.0002\,R_*$ and an opacity of 1.00. The occulting disk must also move at a transverse velocity of $6.637\,\pm\,0.002\,R_*\,\mathrm{day}^{-1}$, which depending on whether it orbits V928 Tau A or B, corresponds to approximately 73.53 or 69.26 $\mathrm{km s}^{-1}$. A search in ground based archival data reveals additional dimming events, some of which suggest periodicity, but no unambiguous period associated with the eclipse observed by K2. We present a new epoch of astrometry which is used to further refine the orbit of the binary, presenting a new lower bound of 67 years, and constraints on the possible orbital periods of the eclipsing companion. The binary is also separated by 18" ($\sim$2250 au) from the lower mass CFHT-BD-Tau 7, which is likely associated with V928 Tau A+B. We also present new high dispersion optical spectroscopy that we use to characterize the unresolved stellar binary.