δ Scuti and RRs Type Variables: Theoretical Aspects
نویسندگان
چکیده
منابع مشابه
Amplitude investigation of δ Scuti variables in open clusters
We report here the results of a statistical analysis of 28 δ Scuti stars from five open clusters, α Persei, Pleiades, Hyades, Praesepe and Coma. These δ Scuti variables, most of which are on the main sequence, tend to show a positive correlation between oscillation amplitude and absolute luminosity. No correlation is found between amplitude and effective temperature .
متن کاملNon - adiabatic theoretical observables in δ Scuti stars
Phase differences and amplitude ratios at different colour photometric bands are currently being used to discriminate pulsation modes in order to facilitate mode identification of κ-driven non-radial pulsating stars. In addition to physical inputs (e.g., mass, T e f f , etc.), these quantities depend on the non-adiabatic treatment of the atmosphere. This paper presents theoretical results conce...
متن کاملIncidence of high-amplitude δ Scuti type variable stars
An order-of-magnitude estimate for the incidence of high-amplitude δ Scuti-type variable stars (HADS) in the δ Scuti area of the H-R diagram is calculated. Using a model for the stellar distribution in the Milky Way, we calculate the number of stars that are expected to fall in the δ Scuti area of the H-R diagram within the magnitude range and sky coverage of the ROTSE Survey for Variables I (R...
متن کاملPeriod changes of δ Scuti stars and stellar evolution
Period changes of δ Scuti stars have been collected or redetermined from the available observations and are compared with values computed from evolutionary models with and without convective core overshooting. For the radial pulsators of Pop. I, the observations indicate (1/P) dP/dt values around 10 year with equal distribution between period increases and decreases. The evolutionary models, on...
متن کاملPhotometry and asteroseismology of δ Scuti stars in Praesepe
We discuss observations and seismic analyses for three multi-periodic δ Scuti stars in the Praesepe cluster: BU, BN and BV Cnc. For two stars (BU and BN Cnc) we re-analyse published photoelectric photometry and show that using statistical weights results in a dramatic reduction in the noise level. We detect seven frequencies in BU Cnc and eight in BN Cnc, with three of the latter being previous...
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ژورنال
عنوان ژورنال: International Astronomical Union Colloquium
سال: 1976
ISSN: 0252-9211
DOI: 10.1017/s0252921100061972