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.
- Pub Date:
- July 2007
- 24 pages. to appear in Science. includes Report and Supplemental Online Materials. Accompanying animation can be found at http://www.astro.lsa.umich.edu/~monnier/Altair2007/altair2007.html