X-shooter Observations of Main-sequence Stars in the Globular Cluster NGC 2808: First Chemical Tagging of a He-normal and a He-rich Dwarf
We present the first chemical composition study of two unevolved stars in the globular cluster NGC 2808, obtained with the X-shooter spectrograph at VLT. NGC 2808 shows three discrete, well-separated main sequences. The most accepted explanation for this phenomenon is that their stars have different helium contents. We observed one star on the
Bragaglia, A. et al.
Fecha de publicación:
9
2010