A large C+N+O abundance spread in giant stars of the globular cluster NGC 1851 (2009)
Yong, David, Grundahl, Frank, D'Antona, Francesca, Karakas, Amanda I., Lattanzio, John C., Norris, John E.
Abundances of C, N, and O are determined in four bright red giants that span the known abundance range for light (Na and Al) and s-process (Zr and La) elements in the globular cluster NGC 1851. The...
Arentoft, Torben, Kjeldsen, Hans, Bedding, Timothy R., Bazot, Michael, Christensen-Dalsgaard, Joergen, Dall, Thomas H., ...
We have carried out a multi-site campaign to measure oscillations in the F5 star Procyon A. We obtained high-precision velocity observations over more than three weeks with eleven telescopes, with...
Nitrogen abundances in giant stars of the globular cluster NGC 6752 (2008)
Yong, David, Grundahl, Frank, Johnson, Jennifer A., Asplund, Martin
We present N abundances for 21 bright giants in the globular cluster NGC 6752 based on high-resolution UVES spectra of the 3360A NH lines. We confirm that the Stromgren c1 index traces the N...
Nitrogen abundances in giant stars of the globular cluster NGC 6752 (2008)
Yong, David, Grundahl, Frank, Johnson, Jennifer A., Asplund, Martin
An abundance analysis of bright giants in the globular cluster NGC 1851 (2007)
We present the chemical compositions for eight bright giants in the globular cluster NGC 1851. Our analysis reveals large star-to-star abundance variations and correlations of the light elements O,...
Pinning Down Gravitational Settling (2006)
Korn, Andreas J., Piskunov, Nikolai, Grundahl, Frank, Barklem, Paul, Gustafsson, Bengt
We analyse high-resolution archival UVES data of turnoff and subgiant stars in the nearby globular cluster NGC 6397 ([Fe/H] = -2). Balmer-profile analyses are performed to derive reddening-free...
Butler, R. Paul, Bouchy, Francois, Brewer, Brendon J, Eggenberger, Patrick, ...
Asteroseismology is a powerful method for determining fundamental properties of stars. We report the first application to a metal-poor object, namely the subgiant star nu Ind. We measured precise...
Bedding, Timothy R., Butler, R. Paul, Carrier, Fabien, Bouchy, Francois, Brewer, Brendon J., Eggenberger, Patrick, ...
Asteroseismology is a powerful method for determining fundamental properties of stars. We report the first application to a metal-poor object, namely the subgiant star nu Ind. We measured precise...
Bedding, Timothy R., Butler, R. Paul, Carrier, Fabien, Bouchy, Francois, Brewer, Brendon J., Eggenberger, Patrick, ...
Asteroseismology is a powerful method for determining fundamental properties of stars. We report the first application to a metal-poor object, namely the subgiant star nu Ind. We measured precise...
Bedding, Timothy R., Butler, R. Paul, Carrier, Fabien, Bouchy, Francois, Brewer, Brendon J., Eggenberger, Patrick, ...
Asteroseismology is a powerful method for determining fundamental properties of stars. We report the first application to a metal-poor object, namely the subgiant star nu Ind. We measured precise...
Bedding, Timothy R., Butler, R. Paul, Carrier, Fabien, Bouchy, Francois, Brewer, Brendon J., Eggenberger, Patrick, ...
Asteroseismology is a powerful method for determining fundamental properties of stars. We report the first application to a metal-poor object, namely the subgiant star nu Ind. We measured precise...
Abundances in giant stars of the globular cluster NGC 6752 (2005)
Yong, David, Grundahl, Frank, Nissen, Poul Erik, Jensen, Henrik Robenhagen, Lambert, David L.
Recent theoretical yields and chemical evolution models demonstrate that intermediate-mass AGB stars cannot reproduce the observed abundance distributions of O, Na, Mg, and Al. As a further...
Distances and ages of NGC 6397, NGC 6752 and 47 Tuc (2003)
Gratton, Raffaele, Bragaglia, Angela, Carretta, Eugenio, Clementini, Gisella, Desidera, Silvano, Grundahl, Frank, ...
Distances and absolute ages for the globular clusters NGC6397, NGC6752, and 47 Tuc are obtained using Main Sequence Fitting. Accurate reddenings and metal abundances (errors of 0.005 mag and 0.04...
Mg isotopic ratios in giant stars of the globular cluster NGC 6752 (2003)
Yong, David, Grundahl, Frank, Lambert, David L., Nissen, Poul Erik, Shetrone, Matthew
Mg isotopic abundance ratios are measured in 20 bright red giants in globular cluster NGC 6752 based on very high-resolution, high signal-to-noise spectra obtained with UVES on the VLT. There is a...
Globular Cluster Ages and Stromgren CCD Photometry (1999)
Stromgren uvby CCD photometry can be used in a variety of ways to constrain the absolute and relative ages of globular clusters. The reddening corrected (v-y, c1) diagram offers the means to derive...
Grundahl, Frank, VandenBerg, Don A., Andersen, Michael I.
We present deep CCD photometry of the globular cluster M13 (NGC 6205) in the Stromgren uvby-Beta system, and determine a foreground reddening of E(b-y)= 0.015mag. From a fit to the main-sequence of...
Hjorth, Jens, Grundahl, Frank, Nilsson, Kari, Festin, Leif
The large-redshift (z=3.8) quasar 1208+1011 has recently been discovered to be a gravitational lens candidate with a separation of 0.47" between the two imaged components (A and B). NOT (Nordic...