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 |