RR Lyrae in M15: Fourier Decomposition and Physical Parameters
نویسندگان
چکیده
منابع مشابه
Fourier Decomposition of RR Lyrae Pulsations: Theory Versus Observations
Fourier decomposition is employed to compare the light curves of RR Lyrae stars with those emerging from hydrodynamic models. Very good agreement is obtained between theory and observation for the RRc stars, but in the case of the RRab stars there are significant discrepancies in the Fourier phase quantities 4>21 and 4>31' The deficiencies of the models are not remedied by replacing Carson opac...
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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 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 کاملShock waves and microturbulence in RR Lyrae
A time variation of the microturbulence velocity vturb in the atmosphere of RR Lyrae is estimated from a comparison of the observed and theoretical FWHM curves of the Fe II 4923.921 Å absorption line. The theoretical line profiles were obtained using a hydrodynamical RR Lyrae model, discussed in Fokin & Gillet (1997). The estimated value of the vturb varies from 2 to 7 km/s, with a maximum at t...
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: Proceedings of the International Astronomical Union
سال: 2006
ISSN: 1743-9213,1743-9221
DOI: 10.1017/s1743921307006114