Results 91 to 100 of about 2,839,036 (384)

The True Nature of the Brightest Local Triple Stellar Candidates within 100 pc in the Galaxy

open access: yesThe Astronomical Journal, 2023
We present a study of a sample of bright ( V ≤ 10 mag) and close ( d ≤ 100 pc) triple–stellar system candidates in the galaxy, consisting of eight systems in total.
Z. T. Yousef   +3 more
doaj   +1 more source

Stellar Yields and Chemical Evolution [PDF]

open access: yesSymposium - International Astronomical Union, 2002
Several speakers at this symposium have alluded to the zeroth-order agreement between the Type II supernovae (SNe) stellar yields, as predicted by the models of those most responsible for driving progress in the field - i.e. Arnett (1991,1996); Maeder (1992); Woosley & Weaver (1995); Langer & Henkel (1995); Thielemann et al.
openaire   +4 more sources

OLDER AND COLDER: THE IMPACT OF STARSPOTS ON PRE-MAIN-SEQUENCE STELLAR EVOLUTION [PDF]

open access: yes, 2015
We assess the impact of starspots on the evolution of late-type stars during the pre-main sequence (pre-MS) using a modified stellar evolution code. We find that heavily spotted models of mass 0.1–1.2 M⊙ are inflated by up to 10% during the pre-MS, and ...
G. Somers, M. Pinsonneault
semanticscholar   +1 more source

Insertion of the FeB cofactor in cNORs lacking metal inserting chaperones

open access: yesFEBS Letters, EarlyView.
Nitric oxide reductase is an enzyme found in the bacterial denitrification pathway. The NOR active site contains a non‐heme iron, often, but not always inserted with the assistance of chaperones. Here, we study the insertion of FeB in the subfamily of cNORs lacking chaperones and found a putative channel, conserved in the family, perhaps enabling the ...
Sofia Appelgren, Pia Ädelroth
wiley   +1 more source

Planetary Nebulae as Probes of Stellar Evolution and Populations [PDF]

open access: yes, 1999
Planetary Nebulae (PNe) have been used satisfactory to test the effects of stellar evolution on the Galactic chemical environment. Moreover, a link exists between nebular morphology and stellar populations and evolution. We present the latest results on Galactic PN morphology, and an extension to a distance unbiased and homogeneous sample of Large ...
arxiv   +1 more source

Asteroseismic Constraints on the Models of Hot B Subdwarfs: Convective Helium-Burning Cores

open access: yesEPJ Web of Conferences, 2017
Asteroseismology of non-radial pulsations in Hot B Subdwarfs (sdB stars) offers a unique view into the interior of core-helium-burning stars. Ground-based and space-borne high precision light curves allow for the analysis of pressure and gravity mode ...
Schindler Jan-Torge   +2 more
doaj   +1 more source

The evolution of the solar–stellar activity [PDF]

open access: yesJournal of Atmospheric and Solar-Terrestrial Physics, 2020
We present a brief review of observational results contributing to modern ideas on the evolution of stellar activity. Basic laws, derived for both rotation-age and activity-rotation relationships, allow us to trace how the activity of low-mass stars changes with age during their stay on the main sequence.
openaire   +3 more sources

Toward a consistent use of overshooting parametrizations in 1D stellar evolution codes [PDF]

open access: yes, 2015
Several parametrizations for overshooting in 1D stellar evolution calculations coexist in the literature. These parametrizations are used somewhat arbitrarily in stellar evolution codes, based on what works best for a given problem, or even for ...
M. Viallet   +3 more
semanticscholar   +1 more source

Taurine promotes glucagon‐like peptide‐1 secretion in enteroendocrine L cells

open access: yesFEBS Letters, EarlyView.
Taurine, a sulfur‐containing amino acid, is likely taken up by enteroendocrine L cells via the taurine transporter. This process increases the levels of cytosolic ATP. The increase in intracellular Ca2+ concentrations and glucagon‐like peptide‐1 secretion through membrane depolarization is caused by the closure of ATP‐sensitive potassium channels ...
Yuri Osuga   +6 more
wiley   +1 more source

The propagation of uncertainties in stellar population synthesis modeling I: The relevance of uncertain aspects of stellar evolution and the IMF to the derived physical properties of galaxies [PDF]

open access: yesAstrophys.J.699:486-506,2009, 2008
The stellar masses, mean ages, metallicities, and star formation histories of galaxies are now commonly estimated via stellar population synthesis (SPS) techniques. SPS relies on stellar evolution calculations from the main sequence to stellar death, stellar spectral libraries, phenomenological dust models, and stellar initial mass functions (IMFs ...
arxiv   +1 more source

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