Massive stars are key astronomical objects for the study of the Universe through spaceand time. Ensuring reliable knowledge about the physical properties, evolution, and feedback of massive stars is of utmost importance forseveral topics at the forefront of modern astrophysics, including, e.g., chemodynamical evolution of galaxies, the reionization of the Universe, the interpretation of extreme astrophysical processes such as black holes, neutron stars, gamma-ray-burts or the recently detected gravitational waves. In addition, the study of massive stars has a more or less direct impact in our theories about star and planet formation, or even the origin and survival of life.

MISSUMA is another step given in the framework of a long-term international project called IACOB, born in 2008 and which is lead and developed from the Instituto de Astrofísica de Canaias. In particular, IACOB is an ambitious project aimed to provide a complete empirical overview of the physical properties of a stastistically significant sample of Galactic OB stars. In particular, the ultimate driver of the project is that the compiled information can be used as strong and long-lasting empirical anchor point for our theories of stellar atmospheres, winds, interior and evolution of blue massive stars. With MISSUMA, we want to benefit from the excellent opportunity make use of: [1] the spectroscopic observations gathered in the last 10 years in the framework of the IACOB project by means an efficient use of optical, high-resolution spectroscopic facilities attached to 1-3m telescopes in the Canary Islands observatories; [2] data about parallaxes and proper motions provided by the successful Gaia-ESA mission; and [3] high temporal cadence photometric data provided by the TESS-NASA space mission, to investigate the various theoretical proposals presented to date about the evolutionary nature of the blue massive supergiants. Despite it is globally accepted that these stars are the evolutionary descendants of those stars born with more that 8 solar masses (the so-called high mass stars), after more than 40 years of research it is not yet clear whether these stars are still in the Main Sequence or in a post-red supergiant evolutionary phase. In addition, we are not sure yet whether these stars are a result of the evolution of single stars or are the products of the evolution of a massive binary system.

In this project we will make use of a large observational dataset provided by IACOB, TESS and Gaia to provide definitive answer to questions which have remainded unsolved for more than 40 years. In addition, the work developed by profesional astrophysicists - not only from the Instituto de Astrofísica de Canarias, but also from other international institutions from Europe and America - in the framework of the MISSUMA project, we plan to develop a series of outreach activities with the aim of exploring ways to drive active participation of part of the canarian society in our willing to solve the longstading mistery of the blue massive supergiants.