Astronomers Say We Owe Our Lives to These Stars
Galaxy CR7 said to contain some of the universe's earliest stars
By Arden Dier,  Newser Staff
Posted Jun 21, 2015 9:00 AM CDT
An artist's impression of galaxy CR7.   (M. Kornmesser/European Southern Observatory)

(Newser) – Astronomers peering through the European Southern Observatory's Very Large Telescope in Chile have discovered a faraway galaxy of stars so significant, they say we wouldn't exist without them. The galaxy, known as Cosmos Redshift 7, or CR7—a name inspired by soccer player Cristiano Ronaldo—is three times brighter than any other galaxy and was born about 12.9 billion years ago, when the universe was a young pup at 800 million years old, reports the New York Times. Experts have long believed that just hydrogen, helium, and small traces of lithium were all that were around to form stars at that time, rather than metals that make up younger stars like our sun. According to theory, they were hundreds or thousands of times bigger than the sun, and as they died, they spewed their remnants into space, eventually producing the first heavy elements, like oxygen, carbon, and iron. However, no evidence of these early stars had been found until now.

Instruments reveal a bright blue cloud within CR7 likely contains only hydrogen and helium, while the galaxy's oldest stars contain no metals, a classification known as Population III. In other words, "those stars were the ones that formed the first heavy atoms that ultimately allowed us to be here," an astronomer says in a press release. "It doesn't really get any more exciting than this." Interestingly, other stars in CR7 are among the "late bloomers" of the earliest stars, reports the Times, meaning they do contain some metals and are known as Population II. (Stars rich in heavy elements, discovered closest to Earth, are considered Population I.) As the study shows that Population III stars "reside amongst regular stars, in brighter galaxies, not just in the earliest, smallest, and dimmest galaxies, which are so faint as to be extremely difficult to study," per the press release, astronomers say finding more should be a bit easier from now on. (Elsewhere, stars may be singing.)