Cosmography of massive stars in the solar neighborhood

Massive stars live shortly — 100 Myr at most — and are therefore excellent tracers of recent star formation activity. Using the 25 years old Hipparcos catalogue, my collaborator João Alves at the University of Vienna and I studied the spatial distribution of massive OB stars in the solar neighborhood, up to approximately 500pc. While previous studies were based on 2D projections of the spatial and velocity distributions, we decided to use modern data mining and full 3-D visualization techniques to look at the distribution of massive stars in 3-D.

The origin of the blue supergiants that define the body and belt of the Orion constellation has long been a mystery. The five giant O and B type stars are located between around 250 and 800 light years from Earth and as a result it was assumed that their origin was not, despite their name, in the prolific Orion Nebula star-forming region, which lies around 1300 light years from Earth. However, the discovery of the Orion stream offers a simple solution. It implies that these relatively distant populations are in fact linked as part of a large galactic structure, which spans more than 1000 light years and at least 25 million years of star formation history.

One exciting find from this study relates to Betelgeuse, the red giant in the arm of Orion. The origin of this star has always been shrouded in mystery but through this study we have uncovered a new loosely organised group – or OB association – named Taurion which we believe to be Betelgeuse's birthplace and to contain its sibling stars.

Link to the European Space Agency Press Release.

Link to the full article published in Astronomy & Astrophysics