LTD064402+245919: A Subgiant with a 1–3 M ⊙ Undetected Companion Identified from LAMOST-TD Data

  title={LTD064402+245919: A Subgiant with a 1–3 M ⊙ Undetected Companion Identified from LAMOST-TD Data},
  author={F. Yang and Bo Zhang and Richard J. Long and Youjun Lu and Su-su Shan and Xing Wei and Jianning Fu and Xian-fei Zhang and Zhi-Chao Zhao and Yu Bai and Tuan Yi and Ling-Lin Zheng and Ze-Ming Zhou and Jifeng Liu},
  journal={The Astrophysical Journal},
Single-line spectroscopic binaries have recently contributed to stellar-mass black hole discovery, independently of the X-ray transient method. We report the identification of a single-line binary system, LTD064402+245919, with an orbital period of 14.50 days. The observed component is a subgiant with a mass of 2.77 ± 0.68 M ⊙, radius 15.5 ± 2.5 R ⊙, effective temperature T eff 4500 ± 200 K, and surface gravity log g 2.5 ± 0.25 dex. The discovery makes use of the Large Sky Area Multi-Object… 
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