منابع مشابه
Double-mode Rr Lyrae Variables: Pulsational Masses Revisited
Double-mode RR Lyrae variables (i.e. radial variables which are simultaneously pulsating in both fundamental and first overtone modes) appear a fundamental tool for investigating the mass of old Population II Horizontal Branch (HB) stars. The most widespread method adopted for evaluating the masses of these objects is based on the Petersen (1973) approach, which relies only on pulsational perio...
متن کاملNew Ccd Observations of the Rr Lyrae Variables in the Oosterhoff Type Ii Cluster M9
CCD observations have been used to study sixteen of the previously known variables in the Oosterhoo type II globular cluster M9. The properties of the RR Lyrae variables in M9 are compared with those in the Oosterhoo type I cluster M3. Methods devised by Simon, Jurcsik and Kovv acs have been used to derive physical parameters for the stars from Fourier analysis. The mean metal abundance so deri...
متن کاملRr Lyrae – Theory Vs Observation
The luminosities, effective temperatures and metallicities that are derived empirically by Kovács and Jurcsik from the light curves of a large number of globular cluster and field RRab and RRc stars are compared to theoretical RR Lyrae models. The strong luminosity dependence of the empirical blue and red edges (LogL vs. LogTeff diagram) is in disagreement with that of both radiative and convec...
متن کاملStrange Cepheids and Rr Lyrae
Strange modes can occur in radiative classical Cepheids and RR Lyrae models. These are vibrational modes that are trapped near the surface as a result of a ’potential barrier’ caused by the sharp hydrogen partial ionization region. Typically the modal number of the strange mode falls between the 7th and 12th overtone, depending on the astrophysical parameters of the equilibrium stellar models (...
متن کاملThe Rr Lyrae Distance Scale
We review seven methods of measuring the absolute magnitude M V of RR Lyrae stars in light of the Hipparcos mission and other recent developments. We focus on identifying possible systematic errors and rank the methods by relative immunity to such errors. For the three most robust methods, statistical parallax, trigonometric parallax, and cluster kinemat-ics, we find M V (at [Fe/H]= −1.6) of 0....
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society: Letters
سال: 2015
ISSN: 1745-3933,1745-3925
DOI: 10.1093/mnrasl/slv024