We present Atacama Large Millimeter/submillimeter Array (ALMA) gas and dust observations at band 7 (339~GHz: 0.89~mm) of the protoplanetary disk around a very low mass star ZZ~Tau~IRS with a spatial resolution of 0\farcs25. The $^{12}$CO~$J=3\rightarrow2$ position--velocity diagram suggests a dynamical mass of ZZ~Tau~IRS of $\sim$0.1--0.3~$M_{\sun}$. The disk has a total flux density of 273.9 mJy, corresponding to an estimated mass of 24--50~$M_\oplus$ in dust. The dust emission map shows a ring at $r=$ 58~au and an azimuthal asymmetry at $r=$ \jh{45}~au with a position angle of 135\degr. The properties of the asymmetry, including radial width, aspect ratio, contrast, and contribution to the total flux, were found to be similar to the asymmetries around intermediate mass stars ($\sim$2~$M_{\sun}$) such as MWC~758 and IRS~48. This implies that the asymmetry in the ZZ~Tau~IRS disk shares a similar origin with others, despite the star being $\sim$10 times less massive. Our observations also suggest that the inner and outer parts of the disk may be misaligned. Overall, the ZZ~Tau~IRS disk shows evidence of giant planet formation at $\sim$10 au scale at a few Myr. If confirmed, it will challenge existing core accretion models, in which such planets have been predicted to be extremely hard to form around very low mass stars.
Early Planet Formation in Embedded Disks (eDisk) XVI: An asymmetric dust disk driving a multi-component molecular outflow in the young Class 0 protostar GSS30 IRS3
An Asymmetric Eclipse Seen Towards the Pre-Main Sequence Binary System V928 Tau
K2观测的弱线金牛座T双星V928 Tau A+B显示了一个单一的，不对称的食的检测，这可能是由于以前未知的亚恒星伴星食的一个组成部分，轨道周期$>$ 66天。在大约9小时的间隔内，双星的一个组成部分会变暗大约60%，大约5小时后恢复正常亮度。从日食形状的模型中，我们发现证据表明，食伴可能被一个圆盘或巨大的环系统所包围。模型化的盘具有$0.9923\,\pm\,0.0005\,R_*$的半径、$56.78\,\pm\, 0.03^\circ$的倾角、$41.22\,\pm\,0.05^\circ$的倾斜度、$-0.2506\,\pm\,0.0002\,R_*$的碰撞参量和1.00的不透明度。掩星盘也必须以$6.637\,\pm\,0.002\,R_*\,\mathrm{day}^{-1}$的横向速度运动，这取决于它是围绕V928 Tau A还是B运行，大约相当于73.53或69.26 $\mathrm{km s}^{-1}$。对地面档案数据的搜索揭示了额外的变暗事件，其中一些表明了周期性，但没有明确的周期与K2观测到的日食相关。我们提出了一个新的时代的天体测量，这是用来进一步完善的轨道的二，提出了一个新的下限为67年，和限制可能的轨道周期的食伴。该双星与较低质量的CFHT-BD-Tau 7也相隔18”（$\sim$ 2250 au），后者可能与V928 Tau A+B有关。我们还提…
Evidence for Systematically Larger Dust Grains in Upper Scorpius Relative to Taurus Disks
Southwest Jiaotong University（西南交通大学）；The University of Arizona（亚利桑那大学）；Peking University（北京大学）；Joint ALMA Observatory（ALMA联合观测站）；California Institute of Technology（加州理工学院）；Texas State University（德克萨斯州立大学）；University of Leeds（利兹大学）；Jet Propulsion Laboratory（喷气推进实验室）；Large Binocular Telescope Observatory（大型双筒望远镜天文台）
