Results 31 to 40 of about 627,744 (337)

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

The solar wind heavy ion composition in the ascending phases of the solar cycles 23 and 25

open access: yesFrontiers in Astronomy and Space Sciences
The approximately 11-year solar cycle has been shown to impact the heavy ion composition of the solar wind, even when accounting for streams of differing speeds; however, the heavy ion composition observed between the same specific phases of a past solar
D. T. Carpenter   +8 more
doaj   +1 more source

Constraining solar abundances using helioseismology [PDF]

open access: yes, 2004
Recent analyses of solar photospheric abundances suggest that the oxygen abundance in the solar atmosphere needs to be revised downwards. In this study we investigate the consequence of this revision on helioseismic analyses of the depth of the solar ...
Antia, H. M., Basu, Sarbani
core   +2 more sources

Bewertung und Verbesserung der Biodiversität in landwirtschaftlichen Gebieten unter besonderer Berücksichtigung von Vogelarten als Bioindikatoren

open access: yesJulius-Kühn-Archiv, 2013
Agricultural landscapes have crucial functions for biodiversity conservation. Contrary to the goals of biodiversity protection the habitat functions and the biological diversity are deteriorating, especially in arable areas.
Hoffmann, Jörg   +5 more
doaj   +1 more source

Integral Field Spectroscopy of Planetary Nebulae with MUSE

open access: yesGalaxies, 2020
The Multi-Unit Spectroscopic Explorer (MUSE) is a large integral field unit mounted on the ESO Very Large Telescope. Its spatial (60 arcsecond field) and wavelength (4800–9300Å) coverage is well suited to detailed imaging spectroscopy of extended ...
Jeremy R. Walsh, Ana Monreal-Ibero
doaj   +1 more source

abundance

open access: yesThe Yale Review
Citation: 'abundance' in the IUPAC Compendium of Chemical Terminology, 5th ed.; International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.14415 • License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International for individual terms.
  +7 more sources

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

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

Akari Observations of Brown Dwarfs. II CO2 as Probe of Carbon and Oxygen Abundances in Brown Dwarfs

open access: yes, 2011
Recent observations with the infrared astronomical satellite AKARI have shown that the CO2 bands at 4.2 micron in three brown dwarfs are much stronger than expected from the unified cloudy model (UCM) based on recent solar C & O abundances.
Allende Prieto   +24 more
core   +1 more source

Galactic Abundances: Report of Working Group 3 [PDF]

open access: yes, 2001
We summarize the various methods and their limitations and strengths to derive galactic abundances from in-situ and remote-sensing measurements, both from ground-based observations and from instruments in space. Because galactic abundances evolve in time
Bothmer, V.   +19 more
core   +1 more source

Home - About - Disclaimer - Privacy