Related papers: Strange pulsation modes in luminous red giants

Using data from the NASA spacecraft Kepler, we study solar-like oscillations in red-giant stars in the open cluster NGC6811. We determine oscillation frequencies, frequency separations, period spacings of mixed modes and mode visibilities…

The properties of radial nonlinear pulsations of massive blue stars are computed with the MESA software instrument in its dynamical mode. Pulsational instabilities could be computationally detected and followed if the evolutionary timestep…

Systematic search for multiperiodicity in the LMC Cepheids (Moskalik, Kolaczkowski & Mizerski 2004) has led to discovery of low amplitude nonradial modes in a substantial fraction of overtone pulsators. We present detailed discussion of…

Red Giant stars host solar-like oscillations which have mixed character, being sensitive to conditions both in the outer convection zone and deep within the interior. The properties of these modes are sensitive to both core rotation and…

Mixed modes observed in red giants allow for investigation of the stellar interior structures. One important feature in these structures is the buoyancy spike caused by the discontinuity of the chemical gradient left behind during the first…

We report for the first time a parametric fit to the pattern of the \ell = 1 mixed modes in red giants, which is a powerful tool to identify gravity-dominated mixed modes. With these modes, which share the characteristics of pressure and…

The red and yellow hypergiants are a rare and important phase in the evolution of the most massive stars that can reach the cool part of the HR Diagram. The hypergiant phase is commonly characterized by high, often episodic mass-loss rates…

In this review we focus on non-linear phenomena in pulsating stars the mode selection and amplitude limitation. Of many linearly excited modes only a fraction is detected in pulsating stars. Which of them and why (the problem of mode…

Betelgeuse is a well known bright red supergiant that shows semi-regular variations with four approximate periods of 2200, 420, 230, and 185 days. While the longest period was customarily regarded as LSP (long secondary period) of unknown…

In this short review on stellar convection dynamics I address the following, currently very topical, issues: (1) the surface effects of the Reynolds stresses and nonadiabaticity on solar-like pulsation frequencies, and (2) oscillation mode…

The surface rotations of some red giants are so fast that they must have been spun up by tidal interaction with a close companion, either another star, a brown dwarf, or a planet. We focus here on the case of red giants that are spun up by…

Context. Observations and analysis of solar-type oscillations in red-giant stars is an emerging aspect of asteroseismic analysis with a number of open questions yet to be explored. Although stochastic oscillations have previously been…

We present a survey of nonradial mode properties in evolutionary sequences of RR Lyrae star models. Attention is focused on the modes that may be driven by the opacity mechanism and on those that may be excited as a consequence of the 1:1…

Solar-like oscillations are excited stochastically by convection. They occur in stars with an outer convection zone, which includes the Sun and other stars on the lower main sequence, as well as cool subgiants and red giants. This chapter…

Rapidly rotating giant stars are relatively rare and may represent important stages of stellar evolution, resulting from stellar coalescence of close binary systems or accretion of sub-stellar companions by their hosting stars. In the…

We have studied a sample of Large Magellanic Cloud red giant binaries that lie on sequence E in the period--luminosity plane. We show that their combined light and velocity curves unambiguously demonstrate that they are binaries showing…

Thanks to the space missions CoRoT and Kepler new oscillation frequencies have been discovered in the Fourier spectra of Blazhko RR Lyrae stars. The period doubling (PD) yields half-integer frequencies between the fundamental mode and its…

Glitches in pulsars are likely to trigger oscillation modes in the fluid interior of neutron stars. We examined these oscillations specifically at r-mode frequencies. The excited r-modes will emit gravitational waves and can have long…

We present spectroscopic and photometric solutions for three spotted systems with red giant components. Absolute physical and orbital parameters for these double-lined detached eclipsing binary stars are presented for the first time. These…

Double-mode RR Lyr type stars are important for studies of properties of horizontal-branch stars. In particular, two periods coupled with spectral properties give a mass estimate that is independent of evolutionary models. Here, we present…