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A leap forward has been performed due to the space-borne missions, MOST, CoRoT and Kepler. They provided a wealth of observational data, and more precisely oscillation spectra, which have been (and are still) exploited to infer the internal structure of stars. While an adiabatic approach is often sufficient to get information on the stellar equilibrium structures it is not sufficient to get a full understanding of the physics of the oscillation. Indeed, it does not permit one to answer some fundamental questions about the oscillations, such as: What are the physical mechanisms responsible for the pulsations inside stars? What determines the amplitudes? To what extent the adiabatic approximation is valid? All these questions can only be addressed by considering the energy exchanges between the oscillations and the surrounding medium. This lecture therefore aims at considering the energetical aspects of stellar pulsations with particular emphasis on the driving and damping mechanisms. To this end, the full non-adiabatic equations are introduced and thoroughly discussed. Two types of pulsation are distinguished, namely the self-excited oscillations that result from an instability and the solar-like oscillations that result from a balance between driving and damping by turbulent convection. For each type, the main physical principles are presented and illustrated using recent observations obtained with the ultra-high precision photometry spaceborne missions (MOST, CoRoT and Kepler). Finally, we consider in detail the physics of scaling relations, which relates the seismic global indices with the global stellar parameters and gave birth to the development of statistical (or ensemble) asteroseismology. Indeed, several of these relations rely on the same cause: the physics of non-adiabatic oscillations. [ABSTRACT FROM AUTHOR]

This lecture on adiabatic oscillations is intended to present the basis of asteroseismology and to serve as an introduction for other lectures of the EES 2014. It also exposes the state-of-the-art of solarlike oscillation analysis, as revealed by the space missions CoRoT and Kepler. A large part of the lecture is devoted to the interpretation of the modes with a mixed character that reveal the properties of the radiative cores of subgiants and red giants. [ABSTRACT FROM AUTHOR]

It is generally accepted that the solar wind is significantly heated beyond ∼10 AU by the turbulent decay of pickup ion generated Alfvénic fluctuations. Here, we present a detailed and general calculation of the pickup ion ionization frequencies, and we evaluate these quantities within the solar wind termination shock along the stagnation line. For this supersonic solar wind region, inside of the solar wind termination shock, our results compare well with earlier estimates of these frequencies. When, in the future, turbulence transport models are extended into the heliosheath, the methodology outlined in this paper can be used to calculate ionization frequencies in this hot and dense plasma region where the resulting calculations become more complex. [ABSTRACT FROM AUTHOR]

Aims. Outflows from accretion disks have been suggested to be suitable sites for producing heavy elements. The objective of this work is to investigate nucleosynthesis in the outflows launched from the inner accretion disks of collapsars that are associated with gamma-ray bursts (GRBs). Methods. By using a collapsar model of advection-dominated accretion and an adiabatic expanding outflow model, we simulated chemical yields inside the outflows associated with GRBs. As a result of the extremely high temperature (above 1010 K), the dominated species existing in the inner region of the disk are proton, neutron, ²H, and 4He, which are photodisintegrated from heavy nuclei. Assuming that an explosive nucleosynthesis could operate in outflows from collapsar accretions associated with GRBs, heavier species including the iron-group will be synthesized significantly. Although various outflow models have been investigated carefully in the past, the uncertainties in predicting the outflow birthplace (ejected-radius rj) in the accretion disk are still quite large. Unlike recent researches on this topic that located the production of heavy elements in GRBs in the outer parts of the disk, in this study we focus our attention mainly on the outflows triggered from the inner region of collapsar accretion. Results. We find 56Ni can be abundantly produced in all the outflow cases considered here from the inner collapsar disk. The highest 56Ni's mass fraction in the outflows reaches 0.463, which can imply that the 56Ni-rich outflows will lead to an observable violent explosion of a GRB event. The mass fractions of 57Ni, 59Cu (decays to 59Ni), and 60Zn (decays to 60Ni) could be 10-2, and the abundance of 58Ni reaches 10-3. Our simulations support that the effective production of heavy elements can occur in the outflows from the inner regions of the collapsar accretion disks. Our results also show that the amount of heavy species produced in outflows depends on the eject-radius rj of the accretion disk where the outflows take place; outflows launched at larger radii can be helpful to increase the quantities of heavy nuclei by means of the lower disk temperature, which agrees with the conclusions of recent studies. Furthermore, a recently published article reported that some nuclei, such as 28Si, 32S, 36Ar, 40Ca, 44Ti, 48Cr, 54Fe, and 55-56Co, experience a dip and then rise in their mass fraction while evolving in the outflow, and this characteristic behavior has occurred in many more outflow cases, and this is reported for the first time in the literature. This characteristic phenomenon also occurs in our nucleosynthetic simulations. [ABSTRACT FROM AUTHOR]