The nature of the Cygnus extreme B-supergiant 2MASS J20395358+4222505

A. Herrero, S. R. Berlanas, A. Gil de Paz +19

2MASS J20395358+4222505 is an obscured early B supergiant near the massive OB star association Cyg OB2. Despite its bright infrared magnitude (K${}_s$=5.82) it has remained largely…