Interferometric Observations of Benchmark Stars for Calibrating Large Stellar Surveys of the Milky Way

• Applicant: Dr. Iva Karovicova, Ph.D.
• Subject Area: Astrophysics and Astronomy
• Term: since 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 409503145

The research aim of the project is to deliver precise stellar parameters of stars that will be used as gold standard stars for large stellar surveys of the Milky Way, e.g., the astrometric space mission Gaia and its ground-based spectroscopic complementary survey Gaia-ESO and many others. I. Karovicova (applicant) obtained interferometric observations of a sample of stars that were chosen in collaboration with stellar survey teams. Those are specially selected stars with an extensive range in metallicity and evolutionary phases. The interferometric observations of these stars obtained by I. Karovicova provide precise measurements of angular diameters and deliver accurate direct determination of effective temperatures. These effective temperatures are spectroscopically model-independent and have much higher accuracy compared to the ones delivered by standard spectroscopic and photometric methods. The directly determined, and fully independent, effective temperatures are essential for testing and improving stellar-atmosphere models and synthetic spectra. Those are required for the correct assessment of the atmospheric parameters of survey sources. The presented project will deliver precise and homogenize parameters for a sample of benchmark stars that will help to calibrate not only the individual surveys such as Gaia, GALAH, APOGEE, and Gaia-ESO, but it will also help to correctly cross-calibrate them. The entire astronomical community will benefit from this study because using a single, homogeneous sample of gold standard stars is the only way how to properly calibrate and cross-calibrate different large stellar surveys and thus fully employ the great potential the survey data hold, and thereby advance our understanding of the structure and evolution of our Galaxy.

• DFG Programme: Research Grants
• International Connection: Australia, Sweden
• Cooperation Partners: Professor Dr. Luca Casagrande; Professorin Dr. Karin Lind, Ph.D.; Dr. Thomas Nordlander; Professor Dr. Peter Tuthill; Dr. Tim White, Ph.D.