Author:
Maryeva Olga,Zhuchkov Roman,Malogolovets Eugene
Abstract
AbstractWe continue the study of O-supergiants belonging to the association Cyg OB2 using moderate-resolution spectra. In this paper we present results of the modelling of the stellar atmosphere of Cyg OB2 #11. This object belongs to the spectral class Ofc, which was recently introduced and is yet small in numbers. Ofc class consists of stars with normal spectra with CIII λλ4647, 4650, 4652 emission lines of comparable intensity to those of the Of-defining lines NIII λλ4634, 4640, 4642. We combined new spectral data obtained by the 1.5-m Russian–Turkish telescope with spectra from MAST and CASU archives and determined physical parameters of the wind and chemical composition of the stellar atmosphere using cmfgen code. The estimated nitrogen abundance is lower than one in atmospheres of ‘normal’ O-supergiants (i.e. O4-6 supergiants without additional spectral index ‘n’ or ‘c’) and carbon abundance is solar. Also we find an excess in silicon. We present an illustrative comparison of our modelling results with current Geneva evolutionary models for rotating massive stars. The position on the Hertzsprung–Russell diagram corresponds to the star mass of about 50 M⊙ and age about 4.5 Myr. Moreover, we carried out the high angular resolution (~ 0.02arcsec) observations on the Russian 6-m telescope aiming to find weaker companions of this star, which did not reveal any.
Publisher
Cambridge University Press (CUP)
Subject
Space and Planetary Science,Astronomy and Astrophysics
Cited by
2 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
1. Properties of Dwarf Stars in Cygnus OB2;Publications of the Astronomical Society of Australia;2016
2. Investigation of the brightest stars in the Cyg OB2 association;Proceedings of the International Astronomical Union;2014-06