National Astronomical Observatory of Japan

First Detection of Thorium in an Extragalactic Star

| Science

The Ursa Minor dwarf galaxy

Astronomers from the National Astronomical Observatory of Japan and Osaka Kyoiku University in Osaka, Japan, have detected the element thorium in a red giant star called COS82, which lies in the Ursa Minor dwarf galaxy. Their discovery marks the first abundance determination of the actinides element thorium in a star beyond the Milky Way, and follows the detection of thorium in more than ten stars within the Milky Way. The derived thorium abundance indicates that the explosive synthesis of heavy elements occurs in similar-type environments in both the Milky Way and the Ursa Minor dwarf galaxy, which is a satellite of the Milky Way.


More info: Subaru telescope web page