THE CHROMOSPHERIC ACTIVITY, AGE, METALLICITY, AND SPACE MOTIONS OF 36 WIDE BINARIES
THE CHROMOSPHERIC ACTIVITY, AGE, METALLICITY, AND SPACE MOTIONS OF 36 WIDE BINARIES
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DOI：
10.1088/0004-6256/141/4/107
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发表时间：
2011-01
期刊：
影响因子：
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通讯作者：
Jingkun Zhao;Jingkun Zhao;T. Oswalt;M. Rudkin;Gang Zhao;Y. Chen
中科院分区：
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作者：
Jingkun Zhao;Jingkun Zhao;T. Oswalt;M. Rudkin;Gang Zhao;Y. Chen
本文给出了36个宽双星系统中41颗F、G、K和M矮星的色球活动（CA）水平、金属丰度和全空间运动。其中31颗双星包含白色矮星（WD）。在这样的二进制中，可以通过将WD的冷却年龄添加到祖星主序列寿命的估计值中来估计总年龄。为了更好地了解CA与恒星年龄的关系，还观察了14颗星团成员星。我们的观测第一次表明，一般来说，对于1.0 <$V − I <$2.4的恒星，CA随年龄从5000万年到至少8 Gyr而衰减。然而，在1 Gyr和5 Gyr之间，V-I < 1.0的恒星的CA水平几乎没有变化，与Pace等人的结果一致。我们的样本还显示出恒星年龄与金属丰度之间的负相关，恒星年龄与W空间速度分量之间的正相关，W速度色散随年龄而增加。最后，人口成员的这些广泛的二进制检查基于其U，V，W的运动学，金属丰度，和CA。我们的结论是，宽双星在这些方面是类似的领域和集群的明星。更重要的是，它们的年龄和金属丰度比附近的星团更连续。
We present the chromospheric activity (CA) levels, metallicities, and full space motions for 41 F, G, K, and M dwarf stars in 36 wide binary systems. Thirty-one of the binaries contain a white dwarf (WD) component. In such binaries, the total age can be estimated by adding the cooling age of the WD to an estimate of the progenitor's main-sequence lifetime. To better understand how CA correlates to stellar age, 14 cluster member stars were also observed. Our observations demonstrate for the first time that, in general, CA decays with age from 50 Myr to at least 8 Gyr for stars with 1.0 ⩽ V − I ⩽ 2.4. However, little change occurs in the CA level for stars with V − I < 1.0 between 1 Gyr and 5 Gyr, consistent with the results of Pace et al. Our sample also exhibits a negative correlation between the stellar age and metallicity, a positive correlation between the stellar age and W space velocity component, and the W velocity dispersion increases with age. Finally, the population membership of these wide binaries is examined based upon their U, V, W kinematics, metallicity, and CA. We conclude that wide binaries are similar to field and cluster stars in these respects. More importantly, they span a much more continuous range in age and metallicity than is afforded by nearby clusters.