Results 31 to 40 of about 52,001 (350)
Non-LTE Abundances of Magnesium, Aluminum and Sulfur in OB Stars Near the Solar Circle [PDF]
, 2002 Non-LTE abundances of magnesium, aluminum and sulfur are derived for a sample of 23 low-v \sin i stars belonging to six northern OB associations of the Galactic disk within 1 kpc of the Sun.
Afflerbach +21 more
core +3 more sources
Neon, sulphur and argon abundances of planetary nebulae in the sub-solar metallicity Galactic anti-centre [PDF]
, 2017 Context: Spectra of planetary nebulae show numerous fine structure emission lines from ionic species, enabling us to study the overall abundances of the nebular material that is ejected into the interstellar medium.
Bernard Salas, J. +2 more
core +3 more sources
Abundances in the Galactic Center [PDF]
Symposium - International Astronomical Union, 1989 Abundance measurements in the Galactic Center (GC) probe material with a nucleosynthetic history unique in our Galaxy. The measurements are of two types: probing interstellar and stellar material. Measurements of gas-phase abundances are mostly toward SgrB2 and SgrA.
openaire +1 more source
The distribution of the elements in the thin disc from classical Cepheids
EPJ Web of Conferences, 2012 Classical Cepheids are the most popular primary distance indicator. They allow us to determine the Galactic abundances gradients and to constrain the chemical enrichment of the thin disc.
Piersimoni A. +8 more
doaj +1 more source
On the Galactic chemical evolution of sulphur. Sulphur abundances from the [S i] 1082 nm line in giants [PDF]
, 2013 Context. The Galactic chemical evolution of sulphur is still under debate. At low metallicities some studies find no correlation between [S/Fe] and [Fe/H], others find [S/Fe] increasing towards lower metallicities, and still others find a combination of ...
Dupree, A. K., Matrozis, E., Ryde, N.
core +1 more source
The galactic abundance gradient from Cepheids [PDF]
Astronomy & Astrophysics, 2003 As a continuation of our previous work on the abundance gradient in the outer part of the galactic disc, this paper presents results on the metallicicty distribution over galactocentric distances up to 15 kpc. The outer disc is clearly separated from the middle part by the existence of a step in the metallicity distribution at about 10 kpc.
R. E. Luck +6 more
openaire +3 more sources
Ages of evolved low mass stars: Central stars of planetary nebulae and white dwarfs
EPJ Web of Conferences, 2013 We have developed several methods to estimate the ages of central stars of planetary nebulae (CSPN), which are based either on observed nebular properties or on data from the stars themselves. Our goal is to derive the age distribution of these stars and
Costa R.D.D. +2 more
doaj +1 more source
A comparison of metal and Ly-α absorption in galactic haloes [PDF]
Serbian Astronomical Journal, 1998 The metallicity structure of galactic haloes is one of the major unknowns in modern galactic astrophysics and observational cosmology. Hereby we outline a very simple method for obtaining at least a crude picture of gas abundances, based on ...
Ćirković M.M.
doaj +1 more source
Stellar Iron Abundances at the Galactic Center [PDF]
, 2000 We present measurements of [Fe/H] for six M supergiant stars and three giant stars within 0.5 pc of the Galactic Center (GC) and one M supergiant star within 30 pc of the GC. The results are based on high-resolution (lambda / Delta lambda =40,000) K-band
Adam Steed +26 more
core +2 more sources
Odessa Astronomical Publications, 2007 We present a new version of the compiled catalogue of nearby stars for which was published the spectoscopically determined effective temperatures, surface gravities, and abundances of iron, magnesium, calcium, silicon, and titanium.
T. V. Borkova +3 more
doaj +1 more source