47 Tucanae precisely dated by SAC team and collaborators
Karsten Brogaard from SAC and collaborators have a paper accepted by MNRAS, to be published on ArXive 14 February 2017, titled "The age of 47Tuc from self-consistent isochrone fits to colour-magnitude diagrams and the eclipsing member V69"
The authors present the to date most thorough age determination of an old globular cluster, plus a method for checking the precision of future age determinations. This will enable us to obtain reliable ages for the oldest stars in the Milky Way.
Best estimate for the age of the globular cluster 47 Tucanae is 11.8 Gyr in satisfactory agreement with the age derived from the white dwarf cooling sequence. The distance is some 16,700 light years, and it is visible to the naked eye.
Authors are: K. Brogaard, D. A. VandenBerg, L. R. Bedin, A. P. Milone, A. Thygesen, and F. Grundahl
Publishing date in Monthly Notices of the Royal Astronomical Society has not yet been determined. A link to the paper in ArXive can be found here.