Related papers: Helioseismic limit on heavy element abundance
An iterative method is presented for reconstructing the height-temperature profile of the solar atmosphere above a sunspot using multi-frequency spectro-polarimetric microwave observations. It is assumed that the emission is formed…
Surges are cool and dense ejections typically observed in chromospheric lines and closely related to other solar phenomena like UV bursts or coronal jets. Our aim is to address the current lack of inverted models and diagnostics of surges…
Helioseismology is the study of the solar interior using observations of oscillations at the surface. It suffers from systematic errors, such as a center-to-limb error in travel-time measurements. Understanding these errors requires a good…
The element settling due to the combined effects of gravity, thermal gradient, radiative acceleration and concentration gradient may lead to important abundance variations inside the stars, which cannot be neglected in the computations of…
This chapter provides a brief introduction to the chemical composition of the Sun. The focus of the chapter is on results obtained from the physical analysis of the solar photosphere. Data obtained from meteorites, solar wind and corona…
We constrain the velocity spectral distribution of global-scale solar convective cells at depth using techniques of local helioseismology. We calibrate the sensitivity of helioseismic waves to large-scale convective cells in the interior by…
In the solar wind an equipartition of kinetic energy densities can be easily established between thermal and suprathermal electrons and the instability conditions are markedly altered by the interplay of these two populations. The new…
Spacecraft observations have shown that the proton temperature in the solar wind falls off with radial distance more slowly than expected for an adiabatic prediction. Usually, previous studies have been focused on the evolution of the…
This paper examines a number of analytic models which can describe the gravitationally stabilized fusion reactor of the Sun. An analytical multiparameter model is shown to reproduce various structure parameters such as density, mass,…
We construct updated solar models with different sets of solar abundances, including the most recent determinations by Asplund et al. (2009). The latter work predicts a larger ($\sim 10%$) solar metallicity compared to previous measurements…
This is a study of abundances of the elements He, C, N, O, Ne, Mg, Si, S, Ar, Ca, and Fe in solar energetic particles (SEPs) in the 2 - 15 MeV amu-1 region measured on the Wind spacecraft during 54 large SEP events occurring between…
Helioseismic waves observable at the solar surface can be used to probe the properties of the Sun's interior. By measuring helioseismic travel times between different location on the surface, flows and other interior properties can be…
High resolution spectra from the Hinode EUV Imaging Spectrometer (EIS) have revealed that coronal spectral line profiles are sometimes asymmetric, with a faint enhancement in the blue wing on the order of 100 km/s. These asymmetries could…
This Letter reports the first observational estimate of the heating rate in the slowly expanding solar corona. The analysis exploits the simultaneous remote and local observations of the same coronal plasma volume with the Solar…
The Sun's corona has interested researchers for multiple reasons, including the search for solution for the famous coronal heating problem and a purely practical consideration of predicting geomagnetic storms on Earth. There exist numerous…
The fundamental processes by which nuclear energy is generated in the Sun have been known for many years. However, continuous progress in areas such as neutrino experiments, stellar spectroscopy and helioseismic data and techniques requires…
The discovery of solar neutrinos confirmed that the inner workings of the Sun generally match our theoretical understanding of the fusion process. Solar neutrinos have also played a role in discovering that neutrinos have mass and that they…
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…
Frequencies of intermediate-degree f-modes of the Sun seem to indicate that the solar radius is smaller than what is normally used in constructing solar models. We investigate the possible consequences of an error in radius on results for…
We argue that it may be possible to exploit neutrinos from the CN cycle and pp chain to determine the primordial solar core abundances of C and N at an interesting level of precision. Such a measurement would allow a comparison of the Sun's…