Related papers: A Study of Multiple-Mode Pulsating Red Giants
We use one-dimensional hydrodynamic calculations combined with synthetic stellar population models of the Magellanic Clouds to study the onset of self-excited pulsation in luminous red giants. By comparing the results with OGLE observations…
We present the results of a systematic search for multiperiodic pulsators among the Galactic Bulge RR Lyrae stars of the OGLE-1 sample. We identify one "canonical" double-mode variable (RRd star) pulsating in two radial modes. In 38 stars…
With the help of linear pulsation models we briefly discuss the peculiar period ratios characteristic for modulated double-mode RR Lyrae stars.
We analyse the OGLE-IV photometry of the first overtone and double-mode RR Lyrae stars (RRc/RRd) in the two fields towards the Galactic bulge observed with high cadence. In 27 per cent of RRc stars we find additional non-radial mode, with…
Red giant stars are solar-like pulsators presenting mixed-modes. Such modes consist in a coupling between pressure waves propagating in the external convective envelope and gravity waves propagating in the radiative interior. Therefore, the…
We present a new grid of non-adiabatic, linear pulsation models of Long-Period Variables (LPVs), including periods and growth rates for radial modes from the fundamental to the fourth overtone. The models span a wide range in mass,…
The Kepler space mission has made it possible to measure the rotational splittings of mixed modes in red giants, thereby providing an unprecedented opportunity to probe the internal rotation of these stars. Asymmetries have been detected in…
We report the discovery of a new group of double-periodic RR Lyrae stars from the analysis of the OGLE-IV Galactic bulge photometry. In 11 stars identified in the OGLE catalog as first overtone pulsators (RRc stars) we detect additional…
The space missions CoRoT and Kepler provide high quality data that allow us to test the transport of angular momentum in stars by the seismic determination of the internal rotation profile. Our aim is to test the validity of the seismic…
We used the OGLE-II and OGLE-III photometry of red giants in the Large Magellanic Cloud to select and study objects revealing ellipsoidal variability. We detected 1546 candidates for long period ellipsoidal variables and 121 eclipsing…
Turbulent motions in the convective envelope of red giants excite a rich spectrum of solar-like oscillation modes. Observations by CoRoT and Kepler have shown that the mode amplitudes increase dramatically as the stars ascend the red giant…
The characteristics of light variation of RSGs in SMC are analyzed based on the nearly 8-10 year long data collected by the ASAS and MACHO projects. The identified 126 RSGs are classified into five categories accordingly: 20 with poor…
Asteroseismology allows us to probe stellar interiors. Mixed modes can be used to probe the physical conditions in red giant cores. However, we still need to identify the physical mechanisms that transport angular momentum inside red…
We present measurements of the dipole mode asymptotic period spacing ($\Delta\Pi_1$), the coupling factor between p- and g- modes ($q$), the g-mode phase offset ($\epsilon_g$), and the mixed-mode frequency rotational splitting…
The detection of mixed modes in red giants with space missions CoRoT and Kepler has revealed their deep internal structure. These modes allow us to characterize the pattern of pressure modes (through the measurement of their asymptotic…
MWC 560 and other peculiar symbiotic binary, CH Cyg, have been classified as the prototypes of the new subclass of symbiotic systems - propellers, with accretion onto a magnetic white dwarf being the source of activity. The companion of the…
Aim: The aim of this work was to search for double mode pulsators among RR Lyr variables of globular cluster Omega Cen. Methods: We conducted a systematic frequency analysis of CASE photometry of Omega Cen RR Lyr stars. We searched for…
We report the discovery of three new triple-mode classical Cepheids in the Large Magellanic Cloud, two of them with the fundamental, first overtone and second overtone excited, and one pulsating simultaneously in the first three overtones.…
Magnetic fields play a significant role in stellar evolution. In the last few years, asteroseismology has enabled the measurement of strong magnetic fields $10^4$--$10^6\,\mathrm{G}$ in the cores of dozens of red giants, and is the only…
We have analysed the photometry of 924 type II Cepheids from the Galactic bulge observed by the Optical Gravitational Lensing Experiment. Our goal was to detect and analyse various dynamical phenomena, including, e.g. multi-mode pulsation,…