We combine published optical and near-infrared photometry to identify new low-mass candidate members in an area of about 0.64 deg^2 in Corona Australis, using the S-parameter method. Five new candidate members of the region are selected, with estimated ages between 3 and 15 Myr, and masses between 0.05 and 0.15 M_Sun. Using Spitzer photometry, we confirm that these objects are not surrounded by optically thick disks. However, one of them is found to display excess at 24 micron, thus suggesting it harbours a disk with an inner hole. With an estimated mass of 0.07 M_Sun according to the SED fitting, this is one of the lowest-mass objects reported to possess a transitional disk.
Including these new members, the fraction of disks is about 50% among the total Corona Australis population selected by the same criteria, lower than the 70% fraction reported earlier for this region. Even so, we find a ratio of transitional to primordial disks (45%) very similar to the value derived by other authors. This ratio is higher than for solar-type stars (5-10%), suggesting that disk evolution is faster in the latter, and/or that the "transitional disk" stage is not such a short-lived step in the case of very low-mass objects. However, this impression needs to be confirmed with better statistics.
The ALMA Legacy survey of Class 0/I disks in Corona australis, Aquila, chaMaeleon, oPhiuchus north, Ophiuchus, Serpens (CAMPOS). I. Evolution of Protostellar disk radii
The Nature of Transition Circumstellar Disks II. Southern Molecular Clouds
过渡盘天体是前主序星，几乎没有或没有近红外线过剩和显着的远红外线过剩，这意味着内部不透明孔在他们的磁盘。在这里，我们提出了一个多频率的研究过渡盘候选人位于狼疮I，III，IV，V，VI，南冕座，天蝎座。补充斯皮策提供的信息与自适应光学（AO）成像（钠钴，VLT），亚毫米测光（APEX），和中阶梯光栅光谱（麦哲伦，杜邦望远镜），我们估计的多重性，磁盘质量，吸积率为每个对象在我们的样本，以确定其内部孔的机制可能负责。我们发现我们的过渡盘在光谱能量分布形态上表现出丰富的多样性，盘质量范围从lsim 1到10 M JUP，吸积率范围从lsim 10 -11到10-7.7 M \odot yr-1。在我们样本中的17个真正的过渡盘中，有三个，九个，三个和两个物体分别与巨大的行星形成，晶粒生长，光蒸发和碎片盘相一致。两个盘可能是环双星，这提供了潮汐截断作为内洞的另一种起源。我们发现同样的异质性的过渡盘人口在狼疮III，IV，南冕在我们以前的分析过渡盘蛇夫座，而所有过渡盘候选人选择在狼疮V，VI原来是污染的背景渐近巨星分支星。所有被归类为光蒸发盘的过渡盘都具有较小的盘质量，这表明光蒸发必须比最新模型预测的效率低。这三个系统是巨大行星的绝佳候选者，它们可能是利用阿塔卡马大型毫米/亚毫米阵列研究行星形成的宝贵实验室。
CSI2264: Simultaneous optical and X-ray variability in the pre-main sequence stars of NGC2264. II: Photometric variability, magnetic activity, and rotation in classIII objects and stars with transition disks
Edge-on disk around the T Tauri star [MR81] Halpha 17 NE in CrA
科勒和他的合作者们使用位于3.5米ESO NTT的斑点照相机SHARP，在南冕座（CrA）恒星形成区的金牛座T星[MR 81] Ha 17东北仅1.3”处发现了一个暗约3.5等的物体，它可能是一颗褐矮星或一颗边缘盘的金牛座T星。我们试图详细研究这个微弱的物体。我们在三个时期获得了深VLT NACO近红外图像，以确定[MR 81] Ha 17和附近的微弱物体是否共同移动，并测量两个物体的红外颜色。我们获得了光学和红外光谱的两个对象与VLT使用FORS和ISAAC，分别确定光谱类型和温度以及年龄和质量。金牛座T星[MR 81] Ha 17和附近的暗天体的投影距离为1369.58质量，即178天文单位，130秒差距。它们共享相同的自行（~5 sigma），因此它们肯定会形成一个束缚双星对。明显较暗的成分[MR 81] Ha 17 NE的光谱类型为M2 e，而明显较亮的成分[MR 81] Ha 17 SW，即先前已知的金牛座T星，光谱类型为M4-5e。我们可以通过目视检查在[MR 81] Ha 17 NE周围识别出一个近边缘的圆盘，其直径至少为30至50 AU。我们能够在[MR 81] Ha 17 NE中检测到强烈的发射线，这几乎可以肯定是由于正在进行的吸积。NE天体只能通过它的散射光来探测。如果这两个天体是同时代的（2- 300万年），并且位于相同的距离（约为CrA的130 pc），那么…
Analysis of the young disk around WRAY 15-1880: does it contain a primitive planetary system?
INAF – Osservatorio Astronomico di Padova（INAF 帕多瓦天文台）；Dipartimento di Fisica e Astronomia “Augusto Righi”, Università di Bologna（博洛尼大学物理与天文学奥古斯托·里吉系）；Dipartimento di Fisica e Astronomia "Galileo Galilei", Università degli Studi di Padova（帕多瓦大学物理与天文学伽利略·伽利莱系）
