报告题目：Exploring Be phenomena in OBA stars: a mid-infrared search
主讲人：简明杰 斯德哥尔摩大学 博士后
时 间：2023年10月10日15:00
地 点：安徽大学磬苑校区理工E楼E400
主办单位：物理与光电工程学院
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报告摘要：
Massive stars are one of the important test labs on how the material behaves in extreme physical situations. As fast rotators, they may experience the Be phenomenon, with the material in their equator be ejected from the star's surface, forming a so-called decretion disk. Long-term optical and IR photometry on fast-rotating massive stars is useful for shedding lights on their formation mechanism. However, most of the previous studies only focused on one optical band, and usually on a few stars. Here we report a systemic search for Be phenomena in the infrared, using the data from the WISE satellite. 916 OBA stars are found to show Be phenomena in the past 13 years, of which 736 are not included in any previous Be catalogs. The brightness variation, with median durations of around 500 days, is strongly correlated with the emission of the H��� line, providing evidence of the association with circumstellar disks. The search for Be phenomena in the WISE bands greatly enlarge the number of stars showing disk variation, and makes multi-band photometry analysis of these events possible, with the help of current and future optical photometry surveys.
报告人简介：
简明杰，斯德哥尔摩大学博士后。博后期间与Karin Lind一起进行了第4次大规模光谱调查。2016年获北京师范大学学士学位，2022年获东京大学博士学位。主要研究兴趣包括从光谱中确定恒星参数，例如使用线深比探测YJ波段的有效温度和对数，10830A氦谱线的行为，以及早期型恒星的光变化。