Along with Frebel, the co-authors of the paper are Joshua D. The paper, “Segue 1: An Unevolved Fossil Galaxy from the Early Universe,” has just been published by Astrophysical Journal. “It’s really adding another dimension to stellar archaeology, where we look back in time to study the era of the first star and first galaxy formation.” “It tells us how galaxies get started,” Frebel says. This galaxy tried to become a big galaxy, but it failed.”īut precisely because it has stayed in the same state, Segue 1 offers valuable information about the conditions of the universe in its early phases after the Big Bang. “This indicates the galaxy never made that many stars in the first place. “It’s chemically quite primitive,” says Anna Frebel, an assistant professor of physics at MIT, and the lead author of a new paper detailing the new findings about Segue 1. Not Segue 1: In contrast to all other galaxies, as the new analysis shows, it appears that Segue 1’s process of star formation halted at what would normally be an early stage of a galaxy’s development. Commonly, stars form from gas clouds and then burn up as supernova explosions after about a billion years, spewing more of the elements that are the basis for a new generation of star formation. Now a team of scientists, including an MIT astronomer, has analyzed that chemical composition and come away with new insights into the evolution of galaxies in the early stages of our universe - or, in this case, into a striking lack of evolution in Segue 1. And it has a rare chemical composition, with vanishingly small amounts of metallic elements present.

It is very small, containing only about 1,000 stars.

Out on the edge of the universe, 75,000 light years from us, a galaxy known as Segue 1 has some unusual properties: It is the faintest galaxy ever detected. Faintest galaxy ever detected illuminates unusual aspects of the universe’s early evolution.

Red giant universe undetected