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Interferometry and the Cepheid Distance Scale


Thomas G. Barnes, III

82 Mt. Locke Road, McDonald Observatory, TX 79734

Presented at the 100th Spring Meeting of the AAVSO, May 23, 2011; received February 9, 2012; accepted February 10, 2012


Systematic uncertainties in the Cepheid distance scale have been greatly reduced in recent years through stellar interferometric observations. Interferometry has made possible direct measurement of Cepheid distances through interferometric pulsation distances. These results compare very well with recent Hubble Space Telescope trigonometric distances. Interferometry has also demonstrated that infrared surface brightness distances are quite reliable, making possible direct comparison of Cepheid luminosities in the Galaxy and the Magellanic Clouds.

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