ARMADA: A Unique Hunt for Exoplanets and Low-Mass Companions around Hot Stars

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

Most known exoplanets have been discovered either through the decrease in starlight when planets transit in front of a star (from our perspective) or through Doppler wavelength shifts in the stellar spectrum. This team will apply a completely different method: imaging a star to determine its wobble due to the tug of a planet as it orbits. The team will use the CHARA and ESO’s VLTI optical interferometry arrays to observe 70 different binary star systems. This is a population of exoplanets that is unlikely to be detectable with other methods. This program will provide the basis for a graduate student to complete a PhD thesis. The team will conduct novel outreach activities through a traveling display in rural Michigan and at NASCAR events. The team will conduct a survey of 70 binary hot star (mass > 1 solar mass) systems to search for massive exoplanets and companion brown dwarfs at orbits of approximately 1 AU. This ARMADA survey will use optical interferometry with the CHARA array in the Northern Hemisphere and ESO’s VLTI array in the Southern Hemisphere to detect stellar wobble due to orbiting massive exoplanets. Their survey will include different separation distances between binary stars in order to examine how binarity might suppress or enhance planet formation as a function of stellar separation of the pair. They will also survey trinary systems for potential exoplanet and low-mass brown dwarf companions. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.