proper motion of 15 stars in the Sculptor Galaxy tagged posts

The movement of stars depends mostly on the invisible dark matter halo around a galaxy. Credit: ESO/Digitized Sky Survey 2

By combining data from Hubble and 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.

Astronomers have long been able to measure the movement of stars in our ‘line of sight’ (i.e. the movement towards or away from us) by measuring the redshift, which is caused by the Doppler effect...