arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2409.09246astro-ph.SR
收藏

两颗质量比极低的全食B型双星的探测

Detection of two totally eclipsing B-type binaries with extremely low mass ratios

Linfeng Chang, Shengbang Qian, Lei Zang, Fuxing Li

AI总结:

研究利用TESS光变曲线和W-D方法发现两颗短周期B9全食双星,测定其极低质量比与绝对参数,推断次子星可能为冷前主序星。

摘要:

探测具有极低质量伴星的O型和B型恒星,对于理解双星的形成与演化非常重要。然而,由于此类系统中的低质量子星对总光通量的贡献极小,发现它们仍然是一项挑战。在利用TESS数据搜寻O型和B型恒星脉动的过程中,我们发现了两颗短周期B型(B9)食双星,其轨道周期分别为1.61613天和2.37857天。通过使用W-D方法分析TESS光变曲线,我们得到了这两颗密近双星的测光解。研究发现,二者均为分离双星,且具有极低的质量比:TIC 260342097为0.067(2),TIC 209148631为0.140(3)。所测定的质量比表明,TIC 260342097是已知B型双星系统中质量比最低的系统之一。我们证明这两个系统均发生全食,并具有宽而平坦的次极小,这意味着测光参数能够被可靠地推导。我们估算了这两颗双星的绝对参数,并发现与正常的低质量、冷主序(MS)恒星相比,两个系统中的次子星均表现出过亮和过大的特征。这些发现可能意味着,这两个系统由一颗B型主序主星和一颗冷的前主序次子星组成,且轨道周期短于2.5天。它们是检验双星形成与演化理论的宝贵目标。

英文摘要:

The detection of O- and B-type stars with extremely low-mass companions is very important for understanding the formation and evolution of binary stars. However, their finding remains a challenge because the low-mass components in such systems contribute such small flux to the total. During the searching for pulsations among O- and B-type stars by using the TESS data, we found two short-period and B-type (B9) eclipsing binaries with orbital periods of 1.61613 and 2.37857 days. Photometric solutions of the two close binaries were derived by analyzing the TESS light curves with the W-D method. It is discovered that both of them are detached binaries with extremely low mass ratios of 0.067(2) for TIC 260342097 and 0.140(3) for TIC 209148631, respectively. The determined mass ratio indicates that TIC 260342097 is one of the lowest mass ratios among known B-type binary systems. We showed that the two systems have total eclipses with a broad and flat secondary minimum, suggesting that the photometric parameters could be derived reliably. The absolute parameters of the two binaries are estimated and it is found that the secondary components in the two systems are over-luminous and over-size when compared with the normal low-mass and cool main-sequence (MS) stars. These findings may imply that the two systems are composed of a B-type MS primary and a cool pre-MS secondary with orbital periods shorter than 2.5 days. They are valuable targets to test theories of binary star formation and evolution.

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。

↑