Birgitta Nordström

Commission 45: spectral classification (2008)

Giridhar, Sunetra, Gray, Richard O., Corbally, Christopher J., Eyer, Laurent, Irwin, Michael J., ...

This report gives an update of developments (since the last General Assembly at Prague) in the areas that are of relevance to the commission. In addition to numerous papers, a new monograph entitled...

Primordial Binaries in the Globular Cluster Omega Centauri (omega Cen) (2007)

Michel Mayor, Antoine Duquennoy, Stéphane Udry, Johannes Andersen, Birgitta Nordström

. In a search for spectroscopic binaries in ! Cen, the radial velocities of 310 giant stars have been monitored with multiple observations over more than ten years. The percentage of binaries with...

Broadband UBVRCIC photometry of horizontal-branch and metal-poor candidates from the HK and Hamburg/ESO surveys. I (2007)

Beers, Timothy C., Flynn, Chris, Rossi, Silvia, Sommer-Larsen, Jesper, Wilhelm, Ronald, Marsteller, Brian, ...

We report broadband UBV and/or BVRCIC CCD photometry for a total of 1857 stars in the thick-disk and halo populations of the Galaxy. The majority of our targets were selected as candidate field...

Metallicities and Ages in the Galactic Disk: a New Sample (2003)

Nordström, Birgitta, Andersen, Johannes, Holmberg, Johan, Jørgensen, Bjarne R.

Metallicities and Ages in the Galactic Disk: A New Large SampleMetallicities ages and full Galactic orbits have been derived for acomplete kinematically unbiased sample of 14.000 F and G dwarfs in...

Are Metallicity and Age Related in the Galactic Disk? (2003)

Nordström, Birgitta, Andersen, Johannes, Holmberg, Johan, Jørgensen, Bjarne R.

Metallicities ages and full Galactic orbits have been derived for acomplete kinematically unbiased sample of 14.000 F and G dwarfs in theSolar neighbourhood. The observational data are Strmgren...

Chemical enrichment in the early galaxy (2003)

Nordström, Birgitta

New, precise abundance data for a large number of elements in a growingsample of extremely metal-poor stars are accumulating from the new 8-mtelescopes. Combined with theoretical models, these...

Local galactic evolution (2003)

Holmberg, Johan, Nordström, Birgitta, Rosenkilde Jørgensen, Bjarne, Andersen, Johannes

The evolution of the Solar neighbourhood is followed using a unique,magnitude complete and kinematically unbiased sample of 14,000 F, G, andK dwarfs. Metallicity, age, space motion and galactic...

First stars. I. The extreme r-element rich, iron-poor halo giant CS31082-001. Implications for the r--process site(s) and radioactive cosmochronology (2002)

Hill, V., Plez, B., Cayrel, R., Beers, T. C., Nordström, Birgitta, Andersen, J., ...

We present a high-resolution ( R= 75 000, S/ N ) spectroscopic analysis of the bright ( V= 11.7), extreme halo giant CS 31082-001([Fe/H] = -2.9), obtained in an ESO-VLT Large Programme dedicated to...

Critical tests of stellar evolution in open clusters (2002)

Meibom, S., Andersen, J., Nordström, Birgitta

We present multiple-epoch radial-velocity observations for 104 stars in a field of the intermediate-age open cluster IC 4651 to . Only 13 stars (13%) of the full sample are field stars. From the 44...

Hur gamla är stjärnorna i Vintergatan? (2002)

Nordström, Birgitta

Astronomerna har nu hittat ett nytt sätt att avgöra en stjärnas ålder. Stjärnan CS31082-001 och grundämnet uran som visade vägen.