منابع مشابه
The Light Curves of RR Lyrae Field Stars
Fourier decompositions have been made of the light curves of a large sample of RR Lyrae field stars. The coefficients have been tabulated. Following the scheme of an earlier investigation of classical Cepheids, certain combinations of the low-order coefficients+,, R,, , and -are plotted against period. The Bailey-type c pulsators stand out from the type ab stars, particularly on the R,, plot wh...
متن کاملNear-field Cosmology with Horizontal Branch and Rr Lyrae Stars
The importance of horizontal branch and RR Lyrae stars is discussed in the context of cosmological arguments for the formation of the Galactic halo and its satellite dwarf galaxies. It is shown, in particular, that the Galactic halo globular cluster system cannot have formed from the accretion of “protogalactic fragments” resembling the very early counterparts of the present-day dwarf satellite...
متن کاملRr Lyrae Stars in the Macho Database
The MACHO Project has catalogued 8000 RR Lyrae stars in the Large Magellanic Cloud, 1800 in the Galactic bulge, and 50 in the Sgr dwarf galaxy. These variables are excellent distance indicators, and are used as tools to study the structure of the Large Magellanic Cloud and the bulge. The large datasets also probe uncommon pulsation modes. A number of double-mode RR Lyrae stars (RRd) are found i...
متن کاملOn The Masses And Luminosities Of RR Lyrae Stars
Some results are given from the comparison with observations of a large number of hydrodynamic pulsation models: (1) Linear pulsation calculations are adequate for the determination of the masses of RRd stars; (2) the Fourier phase parameter 4>31 measures the luminosity-to-mass ratio L/M1.81 for RRc stars; (3) most of the w Cen RRc stars seem to be evolved, as has previously been suggested; (4)...
متن کاملThe absolute magnitudes of RR Lyrae stars from HIPPARCOS parallaxes ?
Using the method of “reduced parallaxes” for the Halo RR Lyrae stars in the hipparcos catalogue we derive a zero point of 0.77 ± 0.26 mag for an assumed slope of 0.18 in the MV-[Fe/H] relation. This is 0.28 magnitude brighter than the value Fernley et al. (1998a) derived by employing the method of statistical parallax for the identical sample and using the same slope. We point out that a simila...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 1990
ISSN: 0004-637X,1538-4357
DOI: 10.1086/169148