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arXiv 1005.4080astro-ph.SR
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2 MASS J20261584-2943124:一个未分辨的L0 .5 + T6谱双星

2MASS J20261584-2943124: An Unresolved L0.5 + T6 Spectral Binary

Christopher R. Gelino, Adam J. Burgasser

摘要:

我们确定L矮星2 MASS J20261584-2943124是一个未解析的光谱双星,基于IRTF/SpeX的低分辨率近红外光谱。数据显示,在1.6微米的一个特殊的吸收功能,以前注意到在其他非常低质量的光谱双星,这可能是由于重叠的FeH和CH 4吸收带的混合光的L矮星/T矮星对的光谱。光谱模板匹配分析表明,组分类型为L0.5和T6,相对亮度Δ H = 4.2+/-0.6。用Keck/NIRC 2进行的激光引导星自适应光学成像观测未能分辨出源,表明在观测历元处的最大间隔为0.25角秒,或者假设距离为36+/-5 pc,则预计的间隔为9 AU。年龄可能相对较大(>5 Gyr)基于系统的大vtan和质量比参数,2 MASS J2026-2943的潜在“大质量”(0.06-0.08 Msun)分量的相对运动可以通过径向速度变化来检测,就像其早期类型的对应物2 MASS J 03202839 -0446358(M8+T5)一样,提供跨越氢燃烧极限的动态质量测量。

英文摘要:

We identify the L dwarf 2MASS J20261584-2943124 as an unresolved spectral binary, based on low-resolution, near-infrared spectroscopy from IRTF/SpeX. The data reveal a peculiar absorption feature at 1.6 microns, previously noted in the spectra of other very low-mass spectral binaries, which likely arises from overlapping FeH and CH4 absorption bands in the blended light of an L dwarf/T dwarf pair. Spectral template matching analysis indicates component types of L0.5 and T6, with relative brightness Delta H = 4.2+/-0.6. Laser guide star adaptive optics imaging observations with Keck/NIRC2 fail to resolve the source, indicating a maximum separation at the observing epoch of 0.25 arcsec, or a projected separation of 9 AU assuming a distance of 36+/-5 pc. With an age that is likely to be relatively older (>5 Gyr based on the system's large vtan and mass ratio arguments, the relative motion of the potentially "massive" (0.06-0.08 Msun) components of 2MASS J2026-2943 may be detectable through radial velocity variations, like its earlier-type counterpart 2MASS J03202839-0446358 (M8+T5), providing dynamical mass measurements that span the hydrogen burning limit.

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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