Open AccessSurface abundances of light elements for a large sample of early B‐type stars – I. Spectral observations of 123 stars; measurements of hydrogen and helium lines; infrared photometry
Author(s) -
Lyubimkov L. S.,
Lambert D. L.,
Rachkovskaya T. M.,
Rostopchin S. I.,
Tarasov A. E.,
Poklad D. B.,
Larionov V. M.,
Larionova L. V.
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03413.x
Subject(s) - physics , stars , balmer series , astrophysics , observatory , photometry (optics) , spectral line , infrared , equivalent width , helium , stellar classification , astronomy , emission spectrum , atomic physics
High‐resolution spectral observations of 123 B0–B5 stars in the main sequence evolutionary phase were obtained at two observatories, namely the McDonald Observatory (McDO) and the Crimean Astrophysical Observatory (CrAO). Accurate equivalent widths W of two Balmer lines, H β and H γ , and ten He i lines were obtained for all the stars, as well as of the He ii λ 4686 line for the hottest ones. A careful analysis of the measured equivalent widths was performed. It is shown that there is a very good agreement between the W values derived from the McDO and CrAO spectra for 14 common stars. A comparison with published data leads to the conclusion that the W values measured earlier by some authors for strong He i lines are very likely to be underestimated. Infrared photometric observations in the J , H , and K bands were performed for 70 programme stars. All these data will be used in other papers: in particular for the T eff and log g determination and for the He, C, N and O abundance analyses.