Results 21 to 30 of about 215,434 (305)

The influence of galactic cosmic rays on ion-neutral hydrocarbon chemistry in the upper atmospheres of free-floating exoplanets [PDF]

, 2014
The authors highlight financial support of the European Community under the FP7 by an ERC starting grant.Cosmic rays may be linked to the formation of volatiles necessary for prebiotic chemistry.
P. B. Rimmer, C. Bilger, Rimmer, P.B., Helling, C., Bilger, C., Ch. Helling   +5 more
core   +1 more source

2D MODELLING OF THE GAS FLOW STRUCTURE IN THE SYMBIOTIC STAR Z ANDROMEDAE

Odessa Astronomical Publications, 2017
The 2D gasdynamical simulations of gas structure in the symbiotic star Z And have been carried out for different stellar wind regimes. Since the mechanisms of gas acceleration in stellar atmospheres are not well studied, the parametric representation of ...
E. Yu. Kilpio
doaj   +1 more source

The Interaction Between Accretion from the Interstellar Medium and Accretion from the Evolved Binary Component in Barium Stars [PDF]

Journal of Astronomy and Space Sciences, 2018
The reanalysis of the previously published abundance pattern of mild barium star HD202109 (ζ Cyg) and the chemical compositions of 129 thin disk barium stars facilitated the search for possible correlations of different stellar parameters with second ...
Yeuncheol Jeong, Alexander V. Yushchenko, Dmytry N. Doikov   +2 more
doaj   +1 more source

The Shapes of Stellar Spectra

Atoms, 2023
Stellar atmospheres separate the hot and dense stellar interiors from the emptiness of space. Radiation escapes from the outermost layers of a star, carrying direct physical information.
Carlos Allende Prieto
doaj   +1 more source

Ionization in atmospheres of brown dwarfs and extrasolar planets. i. The role of electron avalanche [PDF]

, 2010
Brown dwarf and extrasolar planet atmospheres form clouds which strongly influence the local chemistry and physics. These clouds are globally neutral obeying dust-gas charge equilibrium which is, on short timescales, inconsistent with the observation of ...
D. A. Diver, Witte, S., Diver, D.A., S. Witte, Helling, C., Jardine, M., M. Jardine, Helling, Christiane, Diver, D. A., Ch. Helling, Jardine, M.; id_orcid   +10 more
core   +1 more source

Solar and stellar photospheric abundances

Living Reviews in Solar Physics, 2016
The determination of photospheric abundances in late-type stars from spectroscopic observations is a well-established field, built on solid theoretical foundations.
Carlos Allende Prieto
doaj   +1 more source

Diffusion in stellar atmospheres

, 2006
A review of some of the most important studies of the past several decades pertaining to the study of atomic diffusion in stellar atmospheres is presented.
F. LeBlanc
core   +1 more source

Reconstructing enzyme evolution by protein engineering

FEBS Letters, EarlyView.
Natural enzyme evolution can be retraced by protein engineering methods such as directed evolution, rational design, and ancestral sequence reconstruction. These approaches reveal how enzymes emerged from ligand‐binding scaffolds, developed varying substrate preferences, formed oligomeric complexes, adapted to environmental changes, and evolved novel ...
Lukas Drexler, Markus R. Busch, Reinhard Sterner   +2 more
wiley   +1 more source

Statistical Signatures of Nanoflare Activity. III. Evidence of Enhanced Nanoflaring Rates in Fully Convective stars as Observed by the NGTS

The Astrophysical Journal, 2023
Previous examinations of fully convective M-dwarf stars have highlighted enhanced rates of nanoflare activity on these distant stellar sources. However, the specific role the convective boundary, which is believed to be present for spectral types earlier
S. D. T. Grant, D. B. Jess, C. J. Dillon, M. Mathioudakis, C. A. Watson, J. A. G. Jackman, D. G. Jackson, P. J. Wheatley, M. R. Goad, S. L. Casewell, D. R. Anderson, M. R. Burleigh, R. G. West, J. I. Vines   +13 more
doaj   +1 more source

Theoretical research on stellar atmospheres [PDF]

, 1967
History of theoretical research on stellar atmospheres, with ...
Whitney, C. A.
core