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arXiv 1406.2385astro-ph.SRastro-ph.EP
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HIP 114328:一种新的耐高温贫锂太阳能双晶

HIP 114328: a new refractory-poor and Li-poor solar twin

Jorge Melendez, Lucas Schirbel, TalaWanda R. Monroe, David Yong, Ivan Ramirez, Martin Asplund

摘要:

[上下文]。标准的太阳模型无法预测太阳中锂的丰度非常低,比原太阳星云低得多。这个Li问题已经争论了几十年,它被归因于行星形成或长期恒星耗尽。为了测试Li的演化,在一定的年龄范围内找到太阳孪晶是很重要的。此外,对类似太阳的恒星的研究与太阳周围陆地行星形成的特征有关。[方法].我们获得了高分辨率(R= 110,000),高S/N(~300)ESO/VLT UVES光谱的几个太阳孪生候选人和太阳(从小行星朱诺反射)。在太阳双星候选者中,我们将HIP 114328确定为太阳双星,并对这颗恒星相对于太阳的丰度进行了差分逐线分析。【结果】。HIP 114328的恒星参数Teff = 5785+/-10 K,log g = 4.38+/-0.03,[Fe/H] = -0.022+/-0.009,微湍流速度比太阳高0.05+/-0.03 km/s。微分分析表明,这颗恒星在化学性质上与太阳非常相似。其中的难熔元素似乎比太阳中的更少,这意味着HIP 114328可能像太阳一样形成类地行星。HIP 114328的年龄比太阳大2 Gyr,因此是第二古老的太阳双星。它的锂丰度为A(Li)NLTE <= 0.46,比太阳低约4倍(A(Li)NLTE = 1.07 dex),但接近已知最古老的太阳双星HIP 102152。[结论]。基于与其他太阳孪生子相比,HIP 114328的耐火元素丰度较低,似乎是一个很好的岩石行星候选者。这颗恒星的低Li丰度与其年老的年龄相一致,并且非常符合不同年龄太阳双星之间的Li年龄关系。

英文摘要:

[Context]. The standard solar model fails to predict the very low lithium abundance in the Sun, which is much lower than the proto-solar nebula. This Li problem has been debated for decades, and it has been ascribed either to planet formation or to secular stellar depletion. In order to test the evolution of Li, it is important to find solar twins in a range of ages. Also, the study of stars similar to the Sun is relevant in relation to the signature of terrestrial planet formation around the Sun. [Methods]. We acquired high-resolution (R=110,000), high S/N (~300) ESO/VLT UVES spectra of several solar twin candidates and the Sun (as reflected from the asteroid Juno). Among the solar twin candidates we identify HIP 114328 as a solar twin and perform a differential line-by-line abundance analysis of this star relative to the Sun. [Results]. HIP 114328 has stellar parameters Teff = 5785+/-10 K, log g = 4.38+/-0.03, [Fe/H] = -0.022+/-0.009, and a microturbulent velocity 0.05+/-0.03 km/s higher than solar. The differential analysis shows that this star is chemically very similar to the Sun. The refractory elements seem even slightly more depleted than in the Sun, meaning that HIP 114328 may be as likely to form terrestrial planets as the Sun. HIP 114328 is about 2 Gyr older than the Sun, and is thus the second oldest solar twin analyzed at high precision. It has a Li abundance of A(Li)NLTE <= 0.46, which is about 4 times lower than in the Sun (A(Li)NLTE = 1.07 dex), but close to the oldest solar twin known, HIP 102152. [Conclusions]. Based on the lower abundances of refractory elements when compared to other solar twins, HIP 114328 seems an excellent candidate to host rocky planets. The low Li abundance of this star is consistent with its old age and fits very well the emerging Li-age relation among solar twins of different ages.

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。

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