562 citations · 3.3k across the 30 of their papers we have counts for
31 papers
G112-43/44: A metal-poor binary star with a unique chemical composition and kinematics like the Helmi streams
P. E. Nissen, J. S. Silva-Cabrera, W. J. Schuster
G112-43/44, alias BD+00_2058 A and B, is a metal-poor ([Fe/H] = -1.3) wide-orbit binary star with extreme kinematics. We use high-precision determinations of the chemical compositi…
The subgiant HR 7322 as an asteroseismic benchmark star
Amalie Stokholm, Poul Erik Nissen, Victor Silva Aguirre +5
We present an in-depth analysis of the bright subgiant HR 7322 (KIC 10005473) using Kepler short-cadence photometry, optical interferometry from CHARA, high-resolution spectra from…
Carbon, oxygen, and iron abundances in disk and halo stars. Implications of 3D non-LTE spectral line formation
A. M. Amarsi, P. E. Nissen, Á. Skúladóttir
The abundances of carbon, oxygen, and iron in late-type stars are important parameters in exoplanetary and stellar physics, as well as key tracers of stellar populations and Galact…
High-precision stellar abundances of the elements - methods and applications
Poul Erik Nissen, Bengt Gustafsson
Methods to determine abundances of the elements in the atmospheres of F, G, and K stars with precisions of 0.01-0.03 dex are reviewed. Such high-precision stellar abundances have l…
High-precision abundances of elements in Kepler LEGACY stars. Verification of trends with stellar age
P. E. Nissen, V. Silva Aguirre, J. Christensen-Dalsgaard +3
HARPS-N spectra with S/N > 250 and MARCS model atmospheres were used to derive abundances of C, O, Na, Mg, Al, Si, Ca, Ti, Cr, Fe, Ni, Zn, and Y in ten stars from the Kepler LEGACY…
The [Y/Mg] clock works for evolved solar metallicity stars
D. Slumstrup, F. Grundahl, K. Brogaard +5
Previously [Y/Mg] has been proven to be an age indicator for solar twins. Here, we investigate if this relation also holds for helium-core-burning stars of solar metallicity. High…