Improvement of the CORS method for Cepheids radii determination based on Stromgren photometry

Abstract

In this paper we present a modified version of the CORS method based on a new calibration of the Surface Brightness function in the Stromgren photometric system. The method has been tested by means of synthetic light and radial velocity curves derived from nonlinear pulsation models. Detailed simulations have been performed to take into account the quality of real observed curves as well as possible shifts between photometric and radial velocity data. The method has been then applied to a sample of Galactic Cepheids with Stromgren photometry and radial velocity data to derive the radii and a new PR relation. As a result we find log R = (1.19 +- 0.09) + (0.74 +- 0.11) log P (r.m.s=0.07). The comparison between our result and previous estimates in the literature is satisfactory. Better results are expected from the adoption of improved model atmosphere grids.

13 pages including 12 postscript figures and 3 jpeg figures; accepted for publication on A&A

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Cited by in corpus (4)

• CORS Baade-Wesselink method in the Walraven photometric system: the Period-Radius and the Period-Luminosity relation of Classical Cepheids
• Period-colour and amplitude-colour relations in classical Cepheid variables II: the Galactic Cepheid model
• CORS Baade-Wesselink distance to the LMC NGC 1866 blue populous cluster
• Application of the Baade-Wesselink method to a pulsating cluster Herbig Ae star: H254 in IC348