First Surface-resolved Results with the Infrared Optical Telescope Array Imaging Interferometer: Detection of Asymmetries in Asymptotic Giant Branch Stars

  title={First Surface-resolved Results with the Infrared Optical Telescope Array Imaging Interferometer: Detection of Asymmetries in Asymptotic Giant Branch Stars},
  author={Sam Ragland and Wesley A. Traub and J-P. Berger and William C. Danchi and John D. Monnier and Lee Anne Mordy Willson and Nathaniel P. Carleton and Marc G. Lacasse and Rafael Millan-Gabet and Ettore Pedretti and F. Peter Schloerb and W. D. Cotton and Charles H. Townes and Michael K. Brewer and Pierre Haguenauer and Pierre Y. Kern and Pierre Labeye and Fabien Malbet and David F. Malin and Michael R. Pearlman and K. Perraut and Kamal Souccar and Gary Wallace},
  journal={The Astrophysical Journal},
We have measured nonzero closure phases for about 29% of our sample of 56 nearby asymptotic giant branch (AGB) stars, using the three-telescope Infrared Optical Telescope Array (IOTA) interferometer at near-infrared wavelengths (H band) and with angular resolutions in the range 5-10 mas. These nonzero closure phases can only be generated by asymmetric brightness distributions of the target stars or their surroundings. We discuss how these results were obtained and how they might be interpreted… Expand

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