English
Related papers

Related papers: Solar abundances and granulation effects

200 papers

We compare the hot star wind models calculated assuming older solar abundance determination with models calculated using the recently published values derived from 3D hydrodynamical model atmospheres. We show that the use of new abundances…

Astrophysics · Physics 2009-11-13 Jiri Krticka , Jiri Kubat

Stars grow by accreting gas that has an evolving composition owing to the growth and inward drift of dust (pebble wave), the formation of planetesimals and planets, and the selective removal of hydrogen and helium by disk winds. We…

Solar and Stellar Astrophysics · Physics 2021-11-17 Masanobu Kunitomo , Tristan Guillot

Implications of the recently discovered systematic abundance difference between the Sun and two collections of `solar twins' are discussed. The differences can be understood as an imprint on the abundances of the solar convection zone…

Solar and Stellar Astrophysics · Physics 2009-08-26 A. Nordlund

Three-dimensional radiation-hydrodynamics (3D RHD) simulations of stellar surface convection provide valuable insights into many problems in solar and stellar physics. However, almost all 3D near-surface convection simulations to date are…

Solar and Stellar Astrophysics · Physics 2023-09-13 Yixiao Zhou , Anish M. Amarsi , Victor Aguirre Børsen-Koch , Klara G. Karlsmose , Remo Collet , Thomas Nordlander

Solar models using the new lower abundances of Asplund et al. (2005, 2009) or Caffau et al. (2008, 2009) do not agree as well with helioseismic inferences as models that use the higher Grevesse & Noels (1993) or Grevesse & Sauval (1998)…

Solar and Stellar Astrophysics · Physics 2015-05-14 Joyce Ann Guzik , Katie Mussack

The recent downward revision of the solar photospheric abundances now leads to severe inconsistencies between the theoretical predictions for the internal structure of the Sun and the results of helioseismology. There have been claims that…

Astrophysics · Physics 2009-11-13 T. Morel , K. Butler

Very high resolution (R>150,000) spectra of a small sample of nearby K-dwarfs have been acquired to measure the line asymmetries and central wavelength shifts caused by convective motions present in stellar photospheres. This phenomenon of…

Astrophysics · Physics 2007-12-05 I. Ramirez , C. Allende Prieto , D. L. Lambert , M. Asplund

The Sun is the most studied of all stars. It is a reference for all other observed stars and a laboratory of fundamental physics helping us understand processes occuring in conditions irreproducible on Earth. However, our understanding of…

The purpose of this paper is to characterize the statistical properties of solar granulation in the photosphere and low chromosphere up to 650 km. We use velocity and intensity variations obtained at different atmospheric heights from…

Solar and Stellar Astrophysics · Physics 2015-05-14 R. Kostik , E. Khomenko , N. Shchukina

Global hydrodynamic simulations of internal solar dynamics have focused on replicating the conditions for solar-like differential rotation and meridional circulation using the results of helioseismic inversions as a constraint. Inferences…

Flows on the solar surface are linked to solar activity, and LCT is one of the standard techniques for capturing the dynamics of these processes by cross-correlating solar images. However, the link between contrast variations in successive…

Solar and Stellar Astrophysics · Physics 2015-06-16 M. Verma , M. Steffen , C. Denker

Grids of stellar evolution are required in many fields of astronomy/astrophysics, such as planet hosting stars, binaries, clusters, chemically peculiar stars, etc. In this study, a grid of stellar evolution models with updated ingredients…

Solar and Stellar Astrophysics · Physics 2015-12-16 Mutlu Yildiz

We present the result of our investigation on the impact of the low Solar abundance of Asplund and collaborators (2004) on the derived ages for the oldest star clusters based on isochrone fittings. We have constructed new stellar models and…

Solar and Stellar Astrophysics · Physics 2015-05-19 Sukyoung K. Yi , Yong -Cheol Kim

Changes in the solar surface area covered by small-scale magnetic elements are thought to cause long-term changes in the solar spectral irradiance, which are important for determining the impact on Earth's climate. To study the effect of…

Solar and Stellar Astrophysics · Physics 2015-05-20 N. Afram , Y. C. Unruh , S. K. Solanki , M. Schuessler , A. Lagg , A. Voegler

Below 1 mHz, the power spectrum of helioseismic velocity measurements is dominated by the spectrum of convective motions (granulation and supergranulation) making it difficult to detect the low-order acoustic modes and the gravity modes. We…

Astrophysics · Physics 2008-10-31 S. Lefebvre , R. A. Garcia , S. J. Jimenez-Reyes , S. Turck-Chieze , S. Mathur

The Sun is the most studied and well-known star, and as such, solar fundamental parameters are often used to bridge gaps in the knowledge of other stars, when these are required for modelling. However, the two most powerful and precise…

Solar and Stellar Astrophysics · Physics 2020-10-06 Diogo Capelo , Ilídio Lopes

The convectively driven, weakly magnetized regions of the solar photosphere dominate the Sun's surface at any given time, but the temporal variations of these quiet regions of the photosphere throughout the solar cycle are still not well…

Solar and Stellar Astrophysics · Physics 2025-05-05 James Crowley , Ivan Milic , Gianna Cauzzi , Kevin Reardon

Helioseismology and solar modelling have enjoyed a golden era thanks to decades-long surveys from ground-based networks such as for example GONG, BiSON, IRIS and the SOHO and SDO space missions which have provided high-quality helioseismic…

The goal of this research is to investigate how magnetic field affects the dynamics of granular convection and excitation of solar oscillations by means of realistic numerical simulations. We have used a 3D, compressible, non-linear…

Astrophysics · Physics 2008-05-27 L. Jacoutot , A. G. Kosovichev , A. Wray , N. N. Mansour

We are reaching relative maturity and standardization in one-dimensional single-star stellar evolution and pulsation modeling, and are making advances in binary and 2D and 3D models. However, many physical inputs are still uncertain or…

Solar and Stellar Astrophysics · Physics 2014-01-06 Joyce A. Guzik