Astronomy departmental seminar - Fernanda Nieva

OB stars as laboratories for numerous astrophysical fields

OB stars are hot, massive and luminous  blue stars. They are stars of spectral types late-O or early-B and are characterized by strong hydrogen and helium lines. They are short lived and do not move far from where they formed, in loosely organized groups called OB associations. During their lifetime, they emit huge amounts of ultraviolet radiation, ionizing the surrounding interstellar gas. 
In the Milky Way, they are predominantly located on the spiral arms on the main plane of the Galaxy. They provide us with information about numerous fields of Astrophysics. Particularly, precise determinations of their chemical composition constitute fundamental observational constraints to stellar and galactochemical evolution, which are the standard fields where this kind of star traditionally finds its applications. 
What I will show in this seminar is a broader understanding of the importance of a dedicated study of OB stars that potentially can offer an independent test for several other fields. Almost half of the talk will describe how we achieve unprecedented levels of accuracy in chemical abundance determinations. These are main requirements before putting the results into a bigger context.