Spectroscopic observations of the quiescent neutron star system 4U 2129+47 (=V1727 Cygni) M. S. Bothwell, M. A. P. Torres, M. R. Garcia and P. A. Charles A&A, 485 3 (2008) 773-775 Published online: 01 April 2008 DOI: 10.1051/0004-6361:200809516