Related papers: The discrepancy between solar abundances and helio…
Monte Carlo calculations of the Ne K$\alpha$ line fluoresced by coronal x-rays and emitted near the temperature minimum region of the solar atmosphere have been employed to investigate the use of this feature to measure directly the solar…
We consider the formation of solar infrared (2-6 micron) rovibrational bands of carbon monoxide (CO) in CO5BOLD 3D convection models, with the aim to refine abundances of the heavy isotopes of carbon (13C) and oxygen (18O,17O), to compare…
This chapter presents a review on the latest advances in the computation of physical conditions and chemical abundances of elements present in photoionized gas H II regions and planetary nebulae). The arrival of highly sensitive…
Heavy element and helium diffusion are both included for the first time in this series of papers on precise solar models, along with improvements in the input data for nuclear reaction rates, the solar luminosity, the solar age, heavy…
Data obtained over the last three solar cycles have been analysed to reveal the relationships between the intensity of the photospheric field measured along the line of sight by the WSO group at heliolatitudes from -75 to 75 degrees and the…
We re-examine the recombination/collisional emission line (RL/CEL) nebular abundance discrepancy problem in the light of recent high-quality abundance determinations in young stars in the Orion star-forming region. We re-evaluate the CEL…
We re-examine the well-known discrepancy between ionic abundances determined via the analysis of recombination lines (RLs) and collisionally excited lines (CELs). We show that abundance variations can be mimicked in a {\it chemically…
We review the calculation of the solar axion flux from axion-photon and axion-electron interactions and discuss the size of various effects neglected in current calculations. For the Primakoff flux we then explicitly include the partial…
A survey of Ne, O and Fe coronal abundances culled from the recent literature for about 60 late-type stars confirms that the Ne/O ratio of stellar outer atmospheres is about two times the value recently recommended by Asplund et al. The…
Imposing a constraint of the sound-speed profile determined from helioseismology and updating the microphysics, we have revised our seismic solar model, constructed with the assumption of a homogeneous metal abundance distribution, and have…
We present updated standard solar models (SSMs) that incorporate the latest results for nuclear fusion rates, recently published. We show helioseismic results for high and low metallicity compositions and also for an alternative set of…
Precise numerical standard solar models (SSMs) now agree with one another and with helioseismological observations in the convective and outer radiative zones. Nevertheless these models obscure how luminosity, neutrino production and g-mode…
The detection of neutron(n)-capture elements in several planetary nebulae (PNe) has provided a new means of investigating s-process nucleosynthesis in low-mass stars. However, a lack of atomic data has inhibited accurate trans-iron element…
We present a new statistical analysis that combines helioseismology (sound speed, surface helium and convective radius) and solar neutrino observations (the $^8$B and $^7$Be fluxes) to place upper limits to the properties of non standard…
We have used 4752 days of data collected by the Birmingham Solar-Oscillations Network (BiSON) to determine very precise oscillation frequencies of acoustic low-degree modes that probe the solar core. We compare the fine (small frequency)…
In this review we present a brief discussion on the observational evidence in favor of the presence of temperature variations, and conclude that many planetary nebulae show spatial temperature variations that are larger than those predicted…
We estimate the main-sequence age and heavy-element abundance of the Sun by means of an asteroseismic calibration of theoretical solar models using only low-degree acoustic modes from the BiSON. The method can therefore be applied also to…
Helioseismology provides a powerful tool to explore the deep interior of the Sun: for example, the adiabatic sound speed can be inferred with an accuracy of a few parts in 10,000. This has become a serious challenge to theoretical models of…
Since the first observations of solar oscillations, helioseismology has been one of the most successful fields of astrophysics. Data of high quality were obtained through the implementation of networks of ground-based observatories such as…
The compositions of stars are a critical diagnostic tool for many topics in astronomy such as the evolution of our Galaxy, the formation of planets, and the uniqueness of the Sun. Previous spectroscopic measurements indicate a large…