Sentences with phrase «called proper motion»

As expected, the shifts in the star positions as observed on the plane of the sky — called proper motions — are tiny, even over the long time baseline between 2002, when the Hubble observationswere performed, and the first set of publicly released Gaia data, gathered between 2014 and 2015.

Not exact matches

Those measurements, however, were not accurate enough to obtain parallax, and relied instead on tracking the star - forming region's so - called «proper motion» across the plane of the sky.