RT Journal Article SR Electronic T1 Imaging the Surface of Altair JF Science JO Science FD American Association for the Advancement of Science SP 342 OP 345 DO 10.1126/science.1143205 VO 317 IS 5836 A1 Monnier, John D. A1 Zhao, M. A1 Pedretti, E. A1 Thureau, N. A1 Ireland, M. A1 Muirhead, P. A1 Berger, J.-P. A1 Millan-Gabet, R. A1 Van Belle, G. A1 ten Brummelaar, T. A1 McAlister, H. A1 Ridgway, S. A1 Turner, N. A1 Sturmann, L. A1 Sturmann, J. A1 Berger, D. YR 2007 UL http://science.sciencemag.org/content/317/5836/342.abstract AB Spatially resolving the surfaces of nearby stars promises to advance our knowledge of stellar physics. Using optical long-baseline interferometry, we constructed a near-infrared image of the rapidly rotating hot star Altair with a resolution of <1 milliarcsecond. The image clearly reveals the strong effect of gravity darkening on the highly distorted stellar photosphere. Standard models for a uniformly rotating star cannot explain our findings, which appear to result from differential rotation, alternative gravity-darkening laws, or both.