5 papers · 1 filter
Chemical composition of evolved stars in the open cluster M 67
G. Tautvaisiene, B. Edvardsson, I. Tuominen +1
High-resolution spectra of six core helium-burning `clump' stars and three giants in the open cluster M 67 have been obtained with the SOFIN spectrograph on the Nordic Optical Tele…
The rise and fall of the NaMgAl stars
Jocelyn Tomkin, Bengt Edvardsson, David L. Lambert +1
We have made new abundance determinations for a sample of NaMgAl stars. These stars, which are a subgroup of the nearby metal-rich field F and G disk dwarfs, were first identified…
Carbon Abundances in F and G Dwarfs
Helena Andersson, Bengt Edvardsson
We have determined carbon abundances or upper limits from the forbidden [C I] line at 8727.13 A for 85 F and early G type main sequence stars, with metallicities ranging between [F…
Abundance Analysis and Origin of the Zeta Sculptoris Open Cluster
Bengt Edvardsson, Bertil Pettersson, Maryam Kharrazi +1
We have determined chemical abundances and radial velocities for stars in the field of the zeta Sculptoris cluster. We find that the cluster metal deficiency previously found from…
Boron in the Extreme Pop II Star HD 140283 and the Production of Light Elements in the Early Galaxy
B. Edvardsson, B. Gustafsson, S. G. Johansson +4
Using observations of the 2496.7 A B I line with the HST GHRS at a nominal resolution of 90,000, we have found the abundance of boron of HD 140283 to be log epsilon_B (= 12 + log (…