منابع مشابه
Unusual Phase Reversal of Superhumps in ER Ursae Majoris
We studied the evolution of superhumps in the peculiar SU UMa-type dwarf nova, ER UMa. Contrary to the canonical picture of the SU UMa-type superhump phenomena, the superhumps of ER UMa show an unexpected phase reversal during the very early stage (∼5 d after the superoutburst maximum). We interpret that a sudden switch to so-called late superhumps occurs during the very early stage of a supero...
متن کاملThe dynamical stability of W Ursae Majoris-type systems
Theoretical study indicates that a contact binary system would merge into a rapidly rotating single star due to tidal instability when the spin angular momentum of the system is more than a third of its orbital angular momentum. Assuming that W UMa contact binary systems rigorously comply with the Roche geometry and the dynamical stability limit is at a contact degree of about 70%, we obtain th...
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: Astronomische Nachrichten
سال: 1957
ISSN: 0004-6337,1521-3994
DOI: 10.1002/asna.19572840407