Astronomers have assembled the largest-ever compilation of high-precision galaxy distances, called Cosmicflows-4.
Galaxies, such as the Milky Way, are the building blocks of the universe, each comprised of up to several hundred billion stars. Galaxies beyond our immediate neighbourhood are rushing away, faster if they are more distant, which is a consequence of the expansion of the universe that began at the moment of the Big Bang. Measurements of the distances of galaxies, coupled with information about their velocities away from us, determine the scale of the universe and the time that has elapsed since its birth.
“Since galaxies were identified as separate from the Milky Way a hundred years ago, astronomers have been trying to measure their distances,” said Tully, adding, “Now, by combining our more accurate and abundant tools, we are able to measure the distances of galaxies and the related expansion rate of the universe and the time since the universe was born.”