453 citations · 2.3k across the 22 of their papers we have counts for
9 papers · 1 filter
High-precision abundances of elements in solar-type stars. Evidence of two distinct sequences in abundance-age relations
P. E. Nissen, J. Christensen-Dalsgaard, J. R. Mosumgaard +3
HARPS spectra with signal-to-noise ratios S/N > 600 at 6000 A were analysed with MARCS model atmospheres to obtain 1D LTE abundances of C, O, Na, Mg, Al, Si, Ca, Ti, Cr, Fe, Ni, Sr…
Carbon and oxygen in metal-poor halo stars
A. M. Amarsi, P. E. Nissen, M. Asplund +2
Carbon and oxygen are key tracers of the Galactic chemical evolution; in particular, a reported upturn in [C/O] towards decreasing [O/H] in metal-poor halo stars could be a signatu…
Sun-like stars unlike the Sun: Clues for chemical anomalies of cool stars
V. Adibekyan, E. Delgado-Mena, S. Feltzing +11
We present a summary of the splinter session "Sun-like stars unlike the Sun" that was held on 09 June 2016 as part of the Cool Stars 19 conference (Uppsala, Sweden). We discussed t…
Sc and neutron-capture abundances in Galactic low- and high-alpha field halo stars
C. K. Fishlock, D. Yong, A. I. Karakas +5
We determine relative abundance ratios for the neutron-capture elements Zr, La, Ce, Nd, and Eu for a sample of 27 Galactic dwarf stars with -1.5 < [Fe/H] <-0.8. We also measure the…
High-precision abundances of Sc, Mn, Cu, and Ba in solar twins. Trends of element ratios with stellar age
P. E. Nissen
A previous study of correlations between element abundance ratios, [X/Fe], and ages of solar twin stars is extended to include Sc, Mn, Cu, and Ba. HARPS spectra with S/N > 600 are…
Non-LTE analysis of copper abundances for the two distinct halo populations in the solar neighborhood
H. L. Yan, J. R. Shi, P. E. Nissen +1
Two distinct halo populations were found in the solar neighborhood by a series of works. They can be clearly separated by [alpha\Fe] and several other elemental abundance ratios in…