arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 1203.0487astro-ph.SR
收藏

激变变星的罗氏层析成像-- V.飞马座RU上的高纬度星点

Roche tomography of cataclysmic variables - V. A high-latitude star-spot on RU Pegasi

Alexander Dunford, Christopher A Watson, Robert Connon Smith

摘要:

我们目前罗氏断层扫描的第二颗恒星在矮新星系统RU飞马座来自蓝色和红色臂ISIS的数据采取的4.2米威廉赫歇尔望远镜。我们应用熵景观技术来确定系统参数,并得到M1 = 1.06 Msun,M2 = 0.96 Msun,轨道倾角i = 43度,最佳系统速度γ = 7 km/s。这些都是在良好的协议与以前公布的价值观。我们的罗氏层析成像的第二颗星显示出突出的照射的内部拉格朗日点由于照明的光盘和/或亮点,这可能已被增强为RU Peg是在爆发时,我们observation.We发现,这种照射模式是轴对称的,并局限于区域的恒星有一个直接的看法吸积区。这与先前绘制RU Peg的尝试形成对比,RU Peg表明辐照模式是不对称的,并且延伸到终止器之外。我们还检测到恒星原子吸收的表面分布,我们归因于存在一个大的星点的额外的不均匀性。这个光点的中心在纬度82度左右,覆盖了次级线圈总表面积的大约4%。为了与激变变星AE Aqr和BV Cen上的高纬度斑点保持一致,RU Peg上的斑点也似乎稍微向恒星的后半球移动。最后,我们推测,早期的映射尝试,这表明非对称的照射模式,超出了CV捐助者的终结者可能会被解释为对称加热和一个大点的叠加。

英文摘要:

We present Roche tomograms of the secondary star in the dwarf nova system RU Pegasi derived from blue and red arm ISIS data taken on the 4.2-m William Herschel Telescope. We have applied the entropy landscape technique to determine the system parameters and obtained component masses of M1 = 1.06 Msun, M2 = 0.96 Msun, an orbital inclination angle of i = 43 degrees, and an optimal systemic velocity of gamma = 7 km/s. These are in good agreement with previously published values. Our Roche tomograms of the secondary star show prominent irradiation of the inner Lagrangian point due to illumination by the disc and/or bright spot, which may have been enhanced as RU Peg was in outburst at the time of our observations.We find that this irradiation pattern is axi-symmetric and confined to regions of the star which have a direct view of the accretion regions. This is in contrast to previous attempts to map RU Peg which suggested that the irradiation pattern was non-symmetric and extended beyond the terminator. We also detect additional inhomogeneities in the surface distribution of stellar atomic absorption that we ascribe to the presence of a large star-spot. This spot is centred at a latitude of about 82 degrees and covers approximately 4 per cent of the total surface area of the secondary. In keeping with the high latitude spots mapped on the cataclysmic variables AE Aqr and BV Cen, the spot on RU Peg also appears slightly shifted towards the trailing hemisphere of the star. Finally, we speculate that early mapping attempts which indicated non-symmetric irradiation patterns which extended beyond the terminator of CV donors could possibly be explained by a superposition of symmetric heating and a large spot.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑