Through the adoption of the so-called ‘traditional approximation’, a new semi-analytical formula is derived for the light variations produced by low-frequency g modes in uniformly rotating stars. The formula is used to examine the influence of rotation on the variability produced by a stellar model representative of the slowly pulsating B-type class. It is found that, for all apart from prograd...

The observed Magellanic Cloud (MC) Cepheid data pose a new challenge to both stellar structure and stellar evolution. The Fourier analysis of the LMC and SMC data indicate that the 2;1 resonance (P 2 /P 0 5 0.5) between the fundamental mode of pulsation and the second overtone occurs with a period P 0 of 210 days, just as in our Galaxy. The implications of this resonance are difficult to reconc...

Pulsation models are crucial for the interpretation of spectrophotometric and interferometric observations of Mira variables. Comparing predicted and observed spectra is one way of establishing the validity of such models. In this paper, we focus on the models published between 1996 and 1998 by Bessell, Hofmann, Scholz and Wood. A few new model spectra are added, to improve available phase cove...

We utilize nonlinear pulsation models to reproduce the observed light and color curves for two samples of bump Cepheid variables, 19 from the Large Mag-ellanic Cloud and 9 from the Small Magellanic Cloud. This analysis determines the fundamental parameters mass, luminosity, effective temperature, metallicity, distance and reddening for the sample of stars. The use of light curve shape alone to ...

We report the analysis of optical spectra of the extreme helium star LSS 3184 (BX Cir) to determine its effective temperature and gravity throughout its pulsation cycle. The spectra were also used to measure its chemical abundances. We report rest gravity, log g = 3.38 ± 0.02, and a chemical abundance mixture consistent with those reported earlier in a study using an optical spectrum with lower...

We present precise relative radial velocity (RV) measurements for the rapidly oscillating Ap (roAp) star 33 Librae measured from high resolution data spanning the wavelength interval 5000–6200 Å. We find that pulsational radial velocity amplitude determined over a broad wavelength range (≈ 100 Å) depends on the spectral region that is examined and can be as high as 60 m s at 5600 Å and as low a...

purpose: to study the pattern of perfusion of central retinal artery (cra) after 0.1 ml intravitreal injection of bevacizumab to verify the need for any maneuver to decrease the intraocular pressure (iop) including anterior chamber paracentesis (acp) methods: this is a prospective, interventional, noncomparative case series. patients receiving intravitreal injection of bevacizumab for choroidal...

Dark matter remains as an elusive component of modern Cosmology. According to previous research, stellar physics observables can be affected by the presence hypothetical dark particles, which produced or accreted into stars. Stellar pulsations are among matter, because changes internal structure stars due produce variations in pulsation frequencies. We review current research interplay between ...

We demonstrate that there is an inherent symmetry in the way high-overtone stellar pulsations sample the core and the envelope, which can potentially lead to an ambiguity in the asteroseismologically derived locations of internal structures. We provide an intuitive example of the source of this symmetry by analogy with a vibrating string. For the stellar case, we focus on the white dwarf stars,...