Observation techniques of the Baade-Wesselink method

The two observation techniques used for the interferometric version of the Baade-Wesselink method are high-resolution spectroscopy (left) and interferometry (right). The former provides the radial velocity curve over the pulsation cycle of the star. When integrated, this in turn provides the linear radius variation of the star (in metres). The interferometric observations document variation of the star's angular radius. The ratio of these two quantities gives the distance of the Cepheid.

Credit:

ESO

About the Image

Id:eso0432a
Type:Chart
Release date:29 October 2004
Related releases:eso0432
Size:800 x 592 px

About the Object

Name:Interferometry, Spectrograph, Stars
Type:Unspecified : Star : Type : Variable
Category:Illustrations
Stars

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