The Thorium abundance for the red giant COS 82 in the Ursa Minor dwarf spheroidal galaxy is determined based on a high resolution spectrum .
This is the first detection of actinides in an extra Galactic object .
A detailed abundance pattern is determined for 12 other neutron-capture elements from the atomic number 39 to 68 .
These elements are significantly over-abundant with respect to other metals like Fe ( > 1 dex ) and their abundance pattern agrees well with those of the r-process-enhanced , very metal-poor stars known in the Galactic halo , while the metallicity of this object ( [ Fe/H ] \sim - 1.5 ) is much higher than these field stars ( [ Fe/H ] \sim - 3.0 ) .
The results indicate that the mechanism and the astrophysical site that are responsible for neutron-capture elements in COS 82 is similar to that for field r-process-enhanced stars , while the condition of low mass star formation is quite different .
An estimate of the age of this object based on the Th abundance ratio is discussed .