Results 31 to 40 of about 8,281,459 (308)
Frontiers in Astronomy and Space Sciences, 2017 We present the galactic stellar age—velocity dispersion relation obtained from a semi-analytic model of galaxy formation. We divide galaxies into two populations: galaxies which have over-massive/under-massive black holes (BHs) against the best-fitting ...
Hikari Shirakata +3 more
doaj +1 more source
Towards age/rotation/magnetic activity relation with seismology
EPJ Web of Conferences, 2015 The knowledge of stellar ages directly impacts the characterization of a planetary system as it puts strong constraints on the moment when the system was born. Unfortunately, the determination of precise stellar ages is a very difficult task.
Mathur Savita
doaj +1 more source
Uncertainties in asteroseismic grid-based estimates of stellar ages: SCEPtER: Stellar CharactEristics Pisa Estimation gRid [PDF]
, 2014 We study the impact on stellar age determination by means of grid-based techniques adopting asteroseismic constraints of the uncertainty in the radiative opacity, in the initial helium abundance, in the mixing-length value, in the convective core ...
G. Valle +4 more
semanticscholar +1 more source
Stellar population synthesis at the resolution of 2003 [PDF]
, 2003 We present a new model for computing the spectral evolution of stellar populations at ages between 1 x 10 5 and 2 x 10 1 0 yr at a resolution of 3 A across the whole wavelength range from 3200 to 9500 A for a wide range of metallicities.
G. Bruzual, S. Charlot
semanticscholar +1 more source
STELLAR AGES AND CONVECTIVE CORES IN FIELD MAIN-SEQUENCE STARS: FIRST ASTEROSEISMIC APPLICATION TO TWO KEPLER TARGETS [PDF]
, 2013 Using asteroseismic data and stellar evolution models we obtain the first detection of a convective core in a Kepler field main-sequence star, putting a stringent constraint on the total size of the mixed zone and showing that extra mixing beyond the ...
V. Silva Aguirre +23 more
semanticscholar +1 more source
A Search for Stellar Siblings of the ∼200 Myr TOI-251 b Planetary System
The Astrophysical Journal, 2023 Young planets (
Qinghui Sun +6 more
doaj +1 more source
Stellar Ages through the Corners of the Boxy Bulge [PDF]
, 2013 Aims: In some scenarios for the formation of the Milky Way bulge, the stellar population at the edges of the boxy bulge may be younger than those on the minor axis or close to the Galactic center.
E. Valenti +7 more
semanticscholar +1 more source
Three-dimensional Simulations of Massive Stars. II. Age Dependence
The Astrophysical Journal, 2023 We present 3D full star simulations, reaching up to 90% of the total stellar radius, for three 7 M _⊙ stars of different ages: zero-age main sequence (ZAMS), mid–main sequence (midMS), and terminal-age main sequence (TAMS).
R. Vanon +4 more
doaj +1 more source
Quantitative chemical tagging, stellar ages and the chemo-dynamical evolution of the Galactic disc [PDF]
, 2013 The early science results from the new generation of high-resolution stellar spectroscopic surveys, such as Galactic Archaeology with HERMES (GALAH) and the Gaia European Southern Observatory survey (Gaia-ESO), will represent major milestones in the ...
A. Mitschang +14 more
semanticscholar +1 more source
Stellar population constraints on the ages of galactic bars [PDF]
, 2016 © 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. We present a study of the stellar populations within the central regions of four nearby barred galaxies, and use a novel technique to constrain the ...
P. James, S. Percival
semanticscholar +1 more source