On the formation and evolution of magnetic chemically peculiar stars in the solar neighborhood
On the formation and evolution of magnetic chemically peculiar stars in the solar neighborhood
复制标题
太阳邻域磁性化学奇特恒星的形成和演化
DOI：
10.1051/0004-6361:20053272
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发表时间：
2005
影响因子：
6.5
通讯作者：
H. Maitzen
中科院分区：
文献类型：
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作者：
H. Poehnl;E. Paunzen;H. Maitzen
为了对上主序的磁性化学特殊星（CP2）的演化状态施加严格的观测约束，我们研究了在（X， Y）p轨道上距离太阳200 pc半径范围内的一个成熟的星系场CP2天体样本。根据文献中的分类分辨率数据，Hipparcos卫星对182颗恒星进行了精确的视差测量，将其分为Si、SiCr和SrCrEu亚群。首先，研究了CP2现象是否发生在恒星演化的早期阶段，特别是在这些恒星在主序上达到其生命的30%之前。这一结果对于处理恒星发电机、CP2恒星前和主序期间的角动量损失以及恒星演化代码的理论尤其重要。为了对所选样品进行校准，使用了完善的日内瓦7色和Stromgren紫外β光度系统框架。我们能够证明，在1.5 ~ 4.5 M之间的质量中，CP2现象在零年龄主序中连续发生。磁场强度在向末期主层序演化过程中变化不大。似乎只有有效温度和磁场强度才能决定这些恒星的特性。我们发现了CP2恒星在主序演化过程中的几个影响，即存在两个发生剧烈变化的“临界”温度。在Si， SiCr和
In order to put strict observational constraints on the evolutionary status of the magnetic chemically peculiar stars (CP2) of the upper main sequence, we have investigated a well established sample of galactic field CP2 objects within a radius of 200 pc from the Sun in the (X, Y )p lane. In total, 182 stars with accurate parallax measurements from the Hipparcos satellite were divided into Si, SiCr and SrCrEu subgroups based on classification resolution data from the literature. Primarily, it was investigated if the CP2 phenomenon occurs at very early stages of the stellar evolution, significantly before these stars reach 30% of their life-time on the main sequence. This result is especially important for theories dealing with stellar dynamos, angular momentum loss during the pre- as well as main sequence and stellar evolutionary codes for CP2 stars. For the calibration of the chosen sample, the well-developed framework of the Geneva 7-color and Stromgren uvbyβ photometric system was used. We are able to show that the CP2 phenomenon occurs continuously at the zero age main sequence for masses between 1.5 and 4.5 M� .T he magnetic field strengths do not vary significantly during the evolution towards the terminal age main sequence. Only the effective temperature and magnetic field strength seem to determine the kind of peculiarity for those stars. We found several effects during the evolution of CP2 stars at the main sequence, i.e. there are two “critical” temperatures where severe changes take place. There is a transition between Si, SiCr and
CLI0 项目的状态
DOI：
--
发表时间：
2004
期刊：
Classical and Quantum Gravity 21・5
影响因子：
--
作者：
koji Shimomura;Toru Kikuchi;D.-Z.Zeng;S.Miyoki et al.
通讯作者：
S.Miyoki et al.