Results 41 to 50 of about 606,356 (317)

Atomic diffusion in the atmosphere of Feige 86

open access: yesOpen Astronomy, 2017
We have revisited the ultraviolet and optical spectra of the blue horizontal branch star Feige 86. The new analysis finds the star cooler and more compact than previously determined. The IUE spectrum of Feige 86 holds numerous unidentified spectral lines
Németh Péter
doaj   +1 more source

Planetary nebulae in the inner Milky Way [PDF]

open access: yes, 2009
New abundances of planetary nebulae located towards the bulge of the Galaxy are derived based on observations made at LNA (Brazil). We present accurate abundances of the elements He, N, S, O, Ar, and Ne for 56 PNe located towards the galactic bulge.
Chiappini   +7 more
core   +1 more source

Results of 40-year Studies of the X-Ray Binary Cyg X-1 = V1357 Cyg

open access: yesOpen Astronomy, 2016
This paper reviews the results of our 40-year studies of Cyg X-1 using various methods and observational data: mainly optical photometric, spectroscopic, and polarimetric ones, with X-ray data also considered.
Karitskaya E. A.
doaj   +1 more source

Mapping the evolution of mitochondrial complex I through structural variation

open access: yesFEBS Letters, EarlyView.
Respiratory complex I (CI) is crucial for bioenergetic metabolism in many prokaryotes and eukaryotes. It is composed of a conserved set of core subunits and additional accessory subunits that vary depending on the organism. Here, we categorize CI subunits from available structures to map the evolution of CI across eukaryotes. Respiratory complex I (CI)
Dong‐Woo Shin   +2 more
wiley   +1 more source

Understanding the various evolutionary stages of the low-mass star-formation process by SO and SO2

open access: yesFrontiers in Astronomy and Space Sciences
SO and SO2 are two potential candidates to trace the different evolutionary phases of the low-mass star-formation process. Here, we report observations of SO and SO2 along with their isotopologues, 34SO and 34SO2, respectively, in four distinct phases of
Rana Ghosh   +10 more
doaj   +1 more source

Chemical fingerprints of He-sdO stars

open access: yesOpen Astronomy, 2018
The chemical composition of helium-rich hot subluminous O stars plays an important role to understand and model their formation history. We present a spectroscopic analysis of four He-sdO stars,CD-31° 4800, [CW83] 0904- 02, LSS 1274 and LS IV +10° 9. The
Schindewolf Markus   +5 more
doaj   +1 more source

Beryllium abundances along the evolutionary sequence of the open cluster IC 4651 - New test for hydrodynamical stellar models

open access: yes, 2009
[abridged] Previous analyses of lithium abundances in main sequence and red giant stars have revealed the action of mixing mechanisms other than convection in stellar interiors.
C. Charbonnel   +8 more
core   +2 more sources

Plasmodium falciparum gametogenesis essential protein 1 (GEP1) is a transmission‐blocking target

open access: yesFEBS Letters, EarlyView.
This study shows Plasmodium falciparum GEP1 is vital for activating sexual stages of malarial parasites even independently of a mosquito factor. Knockout parasites completely fail gamete formation even when a phosphodiesterase inhibitor is added. Two single‐nucleotide polymorphisms (V241L and S263P) are found in 12%–20% of field samples.
Frederik Huppertz   +5 more
wiley   +1 more source

Planetary nebulae in the inner Milky Way: new abundances [PDF]

open access: yes, 2009
The study of planetary nebulae in the inner-disk and bulge gives important information on the chemical abundances of elements such as He, N, O, Ar, Ne, and on the evolution of these abundances, which is associated with the evolution of intermediate-mass ...
Cavichia, O.   +2 more
core   +2 more sources

Radial Gradients of Abundances [PDF]

open access: yesAstrophysics and Space Science, 2002
We have computed a set of multiphase chemical evolution models in which the radial mass distribution of each theoretical galaxy is calculated using the Universal Rotation Curve from Persic, Salucci & Steel (1996). We obtain the chemical evolution for galaxies of different masses and morphological types by changing the efficiencies to form molecular
Molla, M., Diaz, A. I., Ferrini, F.
openaire   +3 more sources

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