The β Cephei variable in the eclipsing binary HD 92024 . I. Determination of the orbit
The β Cephei variable in the eclipsing binary HD 92024 . I. Determination of the orbit
复制标题
食双星 HD 92024 中的 β Cephei 变星 I. 轨道的确定。
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
S. Ilijić
中科院分区：
文献类型：
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作者：
L. Freyhammer;H. Hensberge;C. Sterken;K. Pavlovski;A. Smette;S. Ilijić
HD 92024 是疏散星团 NGC 3293 的成员；它是南半球已知的唯一具有仙王座β成分的食双星系统。本文首次对单线双星进行了光谱分析，并提供了基于最新高分辨率光谱和光度测定的轨道分析。采用一种推导脉动线剖面变化对径向速度影响最小的轨道元素的方法，我们发现恒星质量分别为 15.0 +3.0 -4.0 M 和 3.0 ± 0.5 M，半径分别为 8.4 ± 0.8 R� 、2 .1 ± 0.4 R� 。温度为 25 500 ± 500 K 和 12 500 ± 1000 K。表面重力值 log g = 3.77 ± 0.08 和 4.27 ± 0.18 表明该双星由演化的早期 B 型主序星和晚 B 型主序伴星组成。由此产生的距离 2.8 ± 0.3 kpc 和系统速度 -16 km s -1 证实了星团成员资格。理论恒星模型显示其年龄为 10−13 Myr，略高于 NGC 3293 最亮成员的文献值。
HD 92024 is a member of the open cluster NGC 3293; it is the only eclipsing binary system with a β Cephei com- ponent known in the southern hemisphere. This paper presents the first spectroscopic analysis of the single-lined binary and provides an orbital analysis based on recent high-resolution spectroscopy and photometry. A procedure to derive orbital el- ements with minimal influence of the pulsational line-profile variations on the radial velocities is applied, and we find the stellar masses to be 15.0 +3.0 −4.0 Mand 3.0 ± 0.5 Mrespectively, and radii of 8.4 ± 0.8 R� ,2 .1 ± 0.4 R� . The temperatures are 25 500 ± 500 K and 12 500 ± 1000 K. The surface gravity values of log g = 3.77 ± 0.08 and 4.27 ± 0.18 indicate that the binary consists of an evolved early B-type primary and a late-B main sequence companion. The resulting distance 2.8 ± 0.3 kpc and systemic velocity −16 km s −1 confirm cluster membership. Theoretical stellar models indicate an age of 10−13 Myr, somewhat higher than the literature value for the brightest members of NGC 3293.