First proper motions measured of stars in a small galaxy outside the Milky Way

By combining data from the Hubble Space Telescope and the Gaia mission, astronomers have been able to measure the proper motion of 15 stars in the Sculptor Galaxy, the first such measurement outside the Milky Way. Analysis shows an unexpected preference in the direction of movement, which suggests that the standard theoretical models used to describe the motion of stars and dark matter halos in other galaxies might be invalid.