摘要
基于日本红外卫星AKARI/FIS的年轻恒星体样本,通过匹配Hipparcos(High Precision Parallax Collecting Satellite)的数据库共计得到21个太阳系附近的年轻恒星体,可靠性为90%.恒星的光谱类型从B型到M型星.利用Hipparcos精确的三角视差测量,定出源在赫罗图位置分布,进而与理论的演化轨迹等时线比较估算恒星的年龄.结果发现样本中存在两个年龄大于10 Myr的年轻恒星体.光学至红外能谱分布表明这两个源是II型年轻恒星体,即有原行星盘.通过进一步的能谱拟合表明这两个源的年龄分别为(14.1±4.2)Myr和(16.8±4.4)Myr.长寿命原行星盘与行星形成关系紧密,是理想的原行星诞生地.
Twenty-one YSOs （Young Stellar Objects） in the solar neighbor have been identified through cross-correlating Hipparcos catalog with AKARI/FIS YSO catalog. The reliability of the match is over 90%. The central objects cover spectral types from B to M. The Hipparcos parallaxes enable us to place the objects in the H-R diagram, which can be used to determine their ages by isochrones. Among these objects, two YSOs have been found whose ages are larger than 10 Myr. The optical to infrared spectral energy distributions （SEDs） of these two YSOs are consistent with those of type II YSOs with protoplanetary disks. Furthermore, fl＇om the SED fitting, the ages of these two sources are constrained to （14.1 ± 4.2） Myr and （16.8 ± 4.4） Myr, respec- tively. Therefore, two YSO candidates with long-lived protoplanetary disks have been detected in AKARI/FIS. The presence of long-lived protoplanetary disks has significant implications for the formation of planets and their host stars.
出处
《天文学报》
CSCD
北大核心
2015年第2期123-129,共7页
Acta Astronomica Sinica
基金
江苏省青年科学基金项目(BK20141046)资助
关键词
恒星:前主序星
原行星盘
三角视差
stars： pre-main sequence, protoplanetary disks, parallaxes
