第二颗Y+Y双星系统的发现：CWISEP J193518.59-154620.3
摘要
我们报告了对Y星际星体CWISEP J193518.59-154620.3的伴侣的发现，这是目前检测到的第二个Y-Y双星系统。Y星是已知最冷的自由浮动天体（<500 K），平均代表通过分子云湍流碎片化直接形成的最低质量天体。研究它们的多性 allows us to place strong constraints on the ability to form planetary mass multiple systems and approaching the opacity limit of fragmentation. Due to their physical properties, Y星也 serve as gas giant planets的类比。CWISEP J193518.59-154620.3已显示其近红外光谱中在3.326 μm处具有独特的甲烷发射特征，可能指示无明确来源的auroral过程。CWISEP J193518.59-154620.3被观察于JWST的MIRI，以F1000W、F1280W和F1800W滤镜观测。我们应用了点扩散函数（PSF）拟合算法，使用经验推导出的PSF模型在F1000W和F1280W滤镜中分辨出伴侣，分离角为172毫弧秒，假设距离为14.43 pc，对应2.48 au。根据ATMO2020演化模型，我们估计主星质量为12-39 M_Jup，伴侣质量为7-24 M_Jup，假设年龄为1-10 Gyr，质量比为0.55-0.62，相应的估计周期为16-28年。尚不清楚该双星系统的哪一颗星体 exhibits该甲烷发射特征。我们也使用MIRI数据分辨已知伴侣WISE J014656.66+423410.0B和WISE J171104.60+350036.8B，并呈现它们的F1000W和F1280W光度。
引用
@article{arxiv.2508.17176,
title = {Discovery of the Second Y+Y Dwarf Binary System: CWISEP J193518.59-154620.3},
author = {Matthew De Furio and Jacqueline Kelly Faherty and Daniella C. Bardalez Gagliuffi and Jonathan Gagné and Eileen C. Gonzales and Rocio Kiman and Marc Kuchner and Federico Marocco and Sherelyn Alejandro Merchan and Melanie Rowland and Adam C. Schneider and Genaro Suárez and Johanna M. Vos},
journal= {arXiv preprint arXiv:2508.17176},
year = {2025}
}
备注
Accepted by ApJL 22 August 2025, 11 pages, 4 figures, 1 table