Physical parameters of three field RR Lyrae stars

الأصل · EN

Strömgren uvby-β photometry of the stars classified as RR Lyrae stars RU Piscium, SS Piscium and TU Ursae Majoris has been used to estimate their iron abundance, temperature, gravity and absolute magnitude. The stability of the pulsating period is discussed. The nature of SS Psc as a RRc or a HADS is addressed. The reddening of each star is estimated from the Strömgren colour indices and reddening sky maps. The results of three approaches to the determination of [Fe/H], T eff and (g) are discussed: Fourier light curve decomposition, the Preston ΔS index and the theoretical grids on the (b-y)ₒ - c₁ₒ plane.