The Sculptor Dwarf Galaxy lies 300,000 light-years away from Earth as it orbits the Milky Way. Image credit: ESA/Hubble/NASA
By combining the data of NASA and the European Space Agency’s (ESA) Hubble Space Telescope and ESA’s Gaia space observatory, astronomers have directly measured the 3D motions of individual stars in the nearby galaxy, the Sculptor Dwarf Galaxy. By doing this, they have achieved an accuracy that has never been measured before for a galaxy outside of our Milky Way. The results from this provide a test for our currently-accepted cosmological model, primarily regarding the distribution of dark matter, and also the galaxy’s trajectory through space.
A team of astronomers from two Dutch astronomy institutes, the Kapteyn Astronomical Institute and the Leiden Observatory, used the data from the two ESA missions, Hubble and Gaia, which span over 12 years. This data allowed them to accurately measure the exact 3D motions of stars within the Sculptor Dwarf Galaxy. This is the first time this has happened with such clarity for a galaxy outside of the Milky Way, 300,000 light years away from Earth.
Davide Massari, of Kapteyn Astronomical Institute, says, “with the precision achieved we can measure the yearly motion of a ...