Magnetism and binarity of the Herbig Ae star V380 Ori
Magnetism and binarity of the Herbig Ae star V380 Ori
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DOI：
10.1111/j.1365-2966.2009.15460.x
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发表时间：
2009-07
影响因子：
4.8
通讯作者：
E. Alecian;G. Wade;C. Català;S. Bagnulo;T. Bohm;J. Bouret;J. Donati;C. Folsom;J. Grunhut;J. Landstreet
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文献类型：
--
作者：
E. Alecian;G. Wade;C. Català;S. Bagnulo;T. Bohm;J. Bouret;J. Donati;C. Folsom;J. Grunhut;J. Landstreet
在本文中，我们报告的结果，高分辨率圆偏振光谱监测赫比格Ae星星V380猎户座，其中我们发现了一个磁场在2005年。对强度谱的仔细研究揭示了一个冷的光谱伴侣的存在。通过对二元光谱进行建模，我们推断出e！主星的有效温度为10500± 500 K，而伴星为5500 ± 500 K，我们认为，主星的高金属丰度（[M/H] = 0.5）可能意味着主星是一颗化学性质特殊的星星。我们观察到次级线的径向速度随时间变化，而初级线的径向速度不随时间变化。通过拟合这些变化，我们得到系统的轨道参数。我们发现它的轨道周期为104 ± 5 d，质量比（MP/MS）大于2.9。强度谱被强、宽和可变的发射严重污染。对这些线的简单分析表明，一个圆盘可能围绕着双星，并且在系统的环境中发生了风。最后，我们进行了磁分析，使用最小二乘解卷积（LSD）的Stokes V光谱的两颗星的配置文件，并采用斜转子模型。根据主星的Stokes V特征的旋转调制，我们推断它的旋转周期P = 4.31276 ± 0.00042 d，并发现它拥有一个中心偶极磁场，极强为2.12 ± 0.15 kG，磁饱和度“= 66 ± 5！，并且旋转轴倾角i = 32 ± 5！.然而，在次级磁场中没有检测到磁场，如果它有偶极磁场，它的强度必须低于500 G，才能与我们的观测结果一致。
In this paper we report the results of high-resolution circular spectropolarimetric monitoring of the Herbig Ae star V380 Ori, in which we discovered a magnetic field in 2005. A careful study of the intensity spectrum reveals the presence of a cool spectroscopic companion. By modelling the binary spectrum we infer the e! ective temperature of both stars: 10500±500K for the primary, and 5500 ± 500 K for the secondary, and we argue that the high metallicity ([M/H] = 0.5), required to fit the lines may imply that the primary is a chemically peculiar star. We observe that the radial velocity of the secondary’s lines varies with time, while that of the the primary does not. By fitting these variations we derive the orbital parameters of the system. We find an orbital period of 104 ± 5 d, and a mass ratio (MP/MS) larger than 2.9. The intensity spectrum is heavily contaminated with strong, broad and variable emission. A simple analysis of these lines reveals that a disk might surround the binary, and that a wind occurs in the environment of the system. Finally, we performed a magnetic analysis using the Least-Squares Deconvolved(LSD) profiles of the Stokes V spectra of both stars, and adopting the oblique rotator model. From rotational modulation of the primary’s Stokes V signatures, we infer its rotation period P = 4.31276 ± 0.00042 d, and find that it hosts a centred dipole magnetic field of polar strength 2.12 ± 0.15 kG, with a magnetic obliquity " = 66 ± 5 ! , and a rotation axis inclination i = 32 ± 5 ! . However, no magnetic field is detected in the secondary, and if it hosts a dipolarmagneticfield, its strengthmust be below about500 G, to be consistent with our observations.