Related papers: Solar-like Oscillations: An Observational Perspect…
Several solar-like stars exhibit cyclic magnetic activity similar to the Sun as found in photospheric and chromospheric emission. We want to understand the physical mechanism involved in rotational dependence of these activity cycle…
In recent years, astronomers have witnessed major progresses in the field of stellar physics. This was made possible thanks to the combination of a solid theoretical understanding of the phenomena of stellar pulsations and the availability…
Magnetohydrodynamic star-in-a-box simulations of convection and dynamos in a solar-like star with different rotation rates are presented. These simulations produce solar-like differential rotation with a fast equator and slow poles, and…
We use the three-dimensional hydrodynamic code of Stein and Nordlund to realistically simulate the upper layers of the solar convection zone in order to study physical characteristics of solar oscillations. Our first result is that the…
Measurements of oscillation frequencies of the Sun and stars can provide important independent constraints on their internal structure and dynamics. Seismic models of these oscillations are used to connect structure and rotation of the star…
Peculiar A stars are so named because they exhibit abundance peculiarities in their atmospheres. It is believed that these arise as a result of differentiation of chemical species in large magnetic spots in which convective mixing is…
Context. The interaction of solar oscillations with near surface convection is poorly understood. These interactions are likely the cause of several problems in helio- and astero-seismology, including the so-called surface effect and…
Convection in the solar interior is thought to comprise structures on a spectrum of scales. This conclusion emerges from phenomenological studies and numerical simulations, though neither covers the proper range of dynamical parameters of…
During their main sequence evolution, massive stars can develop convective regions very close to their surface. These regions are caused by an opacity peak associated with iron ionization. Cantiello et al. (2009) found a possible connection…
Photometric observations made by the NASA Kepler Mission have led to a dramatic increase in the number of main-sequence and subgiant stars with detected solar-like oscillations. We present an ensemble asteroseismic analysis of 76 solar-type…
Among 19 red-giant stars belonging to eclipsing binary systems that have been identified in Kepler data, 15 display solar-like oscillations. We study whether the absence of mode detection in the remaining 4 is an observational bias or…
Oscillations in solar-like oscillators tend to follow an approximately regular pattern in which oscillation modes of a certain degree and consecutive order appear at regular intervals in frequency, i.e. the so-called large frequency…
Hydrodynamical, 3D simulations of the outer layers of the Sun and Alpha Cen A are used to obtain constraints on the properties of turbulent convection in such stars. These constraints enable us to compute - on the base of a theoretical…
We have made high resolution observations of the Sun in which we identify individual sunquakes and see power from these seismic events being pumped into the resonant modes of vibration of the Sun. A typical event lasts about five minutes.…
The CoRoT and Kepler space missions have detected oscillations in hundreds of Sun-like stars and thousands of field red-giant stars. This has opened the door to a new era of stellar population studies in the Milky Way. We report on the…
We present analyses of variability in the red giant stars in the metal-poor globular cluster NGC6397, based on data obtained with the Hubble Space Telescope. We use an non-standard data reduction approach to turn a 23-day observing run…
The richness and very high accuracy of the observed frequencies of solar oscillations provide tight constraints on the structure of the solar interior and hence on the assumptions underlying the calculation of solar models. This permits the…
In recent years there has been some progress towards detecting solar-like oscillations in stars. The goal of this challenging project is to analyse frequency spectra similar to that observed for the Sun in integrated light. In this context…
Unexpected astrophysical observations can be explained by gravitationally captured massive particles, which are produced inside the Sun or other Stars and are accumulated over cosmic times. Their radiative decay in solar outer space would…
Small cyclic variations in the frequencies of acoustic modes are expected to be a common phenomenon in solar-like pulsators, as a result of stellar magnetic activity cycles. The frequency variations observed throughout the solar and stellar…