Classical Cepheids: Yet another version of the Baade-Becker-Wesselink method

TL;DR

This paper introduces a new version of the Baade--Becker--Wesselink method that independently determines reddening, intrinsic color, radius, luminosity, and distance of pulsating stars, improving calibration accuracy.

Contribution

It generalizes previous approaches to calibrate the F(CI) function and applies the method to classical Cepheids, confirming its effectiveness with cluster membership data.

Findings

Results agree with known cluster reddening estimates

Method accurately determines stellar parameters

Applicable to various pulsating star types

Abstract

We propose a new version of the Baade--Becker--Wesselink technique, which allows one to independently determine the colour excess and the intrinsic colour of a radially pulsating star, in addition to its radius, luminosity, and distance. It is considered to be a generalization of the Balona approach. The method also allows the function F(CI) = BC + 10 log (Teff) for the class of pulsating stars considered to be calibrated. We apply this technique to a number of classical Cepheids with very accurate light and radial-velocity curves and with bona fide membership in open clusters (SZ Tau, CF Cas, U Sgr, DL Cas, GY Sge), and find the results to agree well with the reddening estimates of the host open clusters. The new technique can also be applied to other pulsating variables, e.g. RR Lyrae and RV Tauri.