Imaging the Surfaces of Stars

Séminaire IPAG de John Monnier (U. of Michigan), jeudi 10 mai 2012 à 11h00, IPAG seminar room

Under even the best atmospheric conditions, telescope diffraction fundamentally limits the angular resolution for astronomical imaging. Using interferometry, we can coherently combine light from widely-separated telescopes to overcome the single-telescope diffraction limit to boost our imaging resolution by orders of magnitude. I will review recent technical and scientific breakthroughs made possible by the Michigan Infrared Combiner of the CHARA Array on Mt. Wilson, CA, with baselines of 330 meters allowing near-infrared imaging with sub-milli-arcsecond resolution. I will present the first resolved images of main sequence stars besides the Sun, focusing on the oblate and gravity-darkened photospheres of rapidly rotating stars. We can now also resolve the interacting components of close binary stars for the first time and I will highlight the recent remarkable eclipse of epsilon Aurigae as viewed by CHARA.