author={Vikram Ravi and Edward H. Wishnow and Charles H. Townes and Sean A. Lockwood and Hemma Mistry and Kinwah Wu Mullard Space Science Laboratory and Department of Engineering Physics and University of Southern California and Berkeley},
  journal={The Astrophysical Journal},
We present an interferometric study of the continuum surface of the red supergiant star Betelgeuse at 11.15 μm wavelength, using data obtained with the Berkeley Infrared Spatial Interferometer each year between 2006 and 2010. These data allow an investigation of an optically thick layer within 1.4 stellar radii of the photosphere. The layer has an optical depth of ∼1 at 11.15 μm, and varies in temperature between 1900 K and 2800 K and in outer radius between 1.16 and 1.36 stellar radii… Expand

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