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Related papers: Synthetic activity indicators for M-type dwarf sta…

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We present a spectroscopic study and dynamical analysis of ~2600 M7 dwarfs. We confirm our previous finding that the fraction of magnetically active stars decreases with vertical distance from the Galactic plane. We also show that the mean…

We present the results from a spectroscopic study of 1080 nearby active M dwarfs, selected by correlating the 2MASS and ROSAT catalogs. We have derived the spectral types and estimated distances for all of our stars. The spectral types…

Astrophysics · Physics 2008-11-26 Basmah Riaz , John E. Gizis , James Harvin

The radial profiles of gas, stars, and far ultraviolet radiation in 20 dwarf Irregular galaxies are converted to stability parameters and scale heights for a test of the importance of two-dimensional (2D) instabilities in promoting star…

Astrophysics of Galaxies · Physics 2015-06-03 Bruce G. Elmegreen , Deidre A. Hunter

We present the results of realistic, 3D, hydrodynamical, simulations of surface convection in red giant stars with varying effective temperatures and metallicities. We use the convection simulations as time-dependent, hydrodynamical, model…

Astrophysics · Physics 2007-11-21 R. Collet , M. Asplund , R. Trampedach

The ubiquity of M dwarf stars combined with their low masses and luminosities make them prime targets in the search for nearby, habitable exoplanets. We investigate the effects of starspot-induced radial velocity (RV) jitter on detection…

Solar and Stellar Astrophysics · Physics 2015-06-23 Jan Marie Andersen , Heidi Korhonen

Strong surface magnetic fields are ubiquitously found in M-dwarfs with mean intensities on the order of few thousand Gauss-three orders of magnitude higher than the mean surface magnetic field of the Sun. These fields and their interaction…

Solar and Stellar Astrophysics · Physics 2010-12-08 D. Shulyak , A. Reiners , S. Wende , O. Kochukhov , N. Piskunov , A. Seifahrt

In this contribution, we present the StaggerGrid, a collaborative project for the construction of a comprehensive grid of time-dependent, three-dimensional (3D), hydrodynamic model atmospheres of solar- and late-type stars with different…

Solar and Stellar Astrophysics · Physics 2015-05-30 Remo Collet , Zazralt Magic , Martin Asplund

We present an investigation of the velocity fields in early to late M-type star hydrodynamic models, and we simulate their influence on FeH molecular line shapes. The M star model parameters range between log g of 3.0 - 5.0 and Teff of 2500…

Solar and Stellar Astrophysics · Physics 2015-05-14 S. Wende , A. Reiners , H. -G. Ludwig

Low-mass stars show evidence of vigorous magnetic activity in the form of large flares and coronal mass ejections. Such space weather events may have important ramifications for the habitability and observational fingerprints of…

Earth and Planetary Astrophysics · Physics 2021-07-19 Howard Chen , Zhuchang Zhan , Allison Youngblood , Eric T. Wolf , Adina D. Feinstein , Daniel E. Horton

Effective temperatures, surface gravities, and iron abundances were derived for 109 stars observed by the K2 mission using equivalent width measurements of Fe I and Fe II lines. Calculations were carried out in LTE using Kurucz model…

Solar and Stellar Astrophysics · Physics 2024-07-19 V. Loaiza-Tacuri , Katia Cunha , Verne V. Smith , F. Quispe-Huaynasi , Ellen Costa-Almeida , Luan Ghezzi , Jorge Melendez

Solar-type stars exhibit a rich variety of magnetic activity. Seeking to explore the convective origins of this activity, we have carried out a series of global 3D magnetohydrodynamic (MHD) simulations with the anelastic spherical harmonic…

Solar and Stellar Astrophysics · Physics 2015-06-12 Nicholas J. Nelson , Benjamin P. Brown , A. Sacha Brun , Mark S. Miesch , Juri Toomre

We present NIR synthetic spectra based on PHOENIX stellar atmosphere models of typical early and mid M dwarfs with varied C and O abundances. We apply multiple recently published methods for determining M dwarf metallicity to our models to…

Solar and Stellar Astrophysics · Physics 2016-09-21 Mark J. Veyette , Philip S. Muirhead , Andrew W. Mann , France Allard

M dwarfs are prime targets for exoplanet searches due to their low masses and radii, which enable the detection of small planets in their habitable zones (HZs). However, the magnetic activity of M dwarfs can introduce signals in radial…

Solar and Stellar Astrophysics · Physics 2026-03-05 C. G. Oviedo , A. P. Buccino , R. F. Díaz , R. Petrucci , E. Jofré , I. Boisse , P. D. Colombo , X. Delfosse

The present sequence of two articles reports on a custom-built toolkit implementing a technique similar to multi-directional medical tomography to simulate and visualize the composite 3D structure of winds from hot close double stars. In…

Multimedia · Computer Science 2018-05-02 I. Pachoulakis

In this paper we present a numerical study of the time evolution of solar prominences embedded in sheared magnetic arcades. The prominence is represented by a density enhancement in a background stratified atmosphere and is connected to the…

Solar and Stellar Astrophysics · Physics 2015-06-23 J. Terradas , R. Soler , M. Luna , R. Oliver , J. L. Ballester

We run numerical simulations of molecular clouds (MCs), adopting properties similar to those found in the Central Molecular Zone (CMZ) of the Milky Way. For this, we employ the moving mesh code Arepo and perform simulations which account…

Astrophysics of Galaxies · Physics 2016-09-21 Erik Bertram , Simon C. O. Glover , Paul C. Clark , Sarah E. Ragan , Ralf S. Klessen

We investigate the effect of stellar activity and flares on short-term radial velocity measurements in the mid-M flare star CN Leo. Radial velocity variations are calculated from 181 UVES spectra obtained during three nights. We searched…

Solar and Stellar Astrophysics · Physics 2015-05-13 Ansgar Reiners

The aim of this work is to investigate and characterise particle behaviour in an (observationally-driven) 3D MHD model of the solar atmosphere above a slowly evolving, non-flaring active region. We use a relativistic guiding-centre particle…

Solar and Stellar Astrophysics · Physics 2016-02-17 J. Threlfall , Ph. -A. Bourdin , T. Neukirch , C. E. Parnell

We present here additional results of a spectropolarimetric survey of a small sample of stars ranging from spectral type M0 to M8 aimed at investigating observationally how dynamo processes operate in stars on both sides of the full…

Stellar activity cycles are the manifestation of dynamo process running in the stellar interiors. They have been observed during years to decades thanks to the measurement of stellar magnetic proxies at the surface of the stars such as the…

Solar and Stellar Astrophysics · Physics 2015-06-12 S. Mathur , R. A. Garcia , A. Morgenthaler , D. Salabert , P. Petit , J. Ballot , C. Regulo , C. Catala