Observations of light from a far galaxy further indicate that stellar formation began early
NASA, ESA, W. Zheng/JHU, M. Postman/STScI and the CLASH Team
A measly 250 million years after the Big Bang, in a galaxy far, far away, what may be some of the first stars in the universe began to twinkle. If today’s 13.8-billion-year-old universe is in middle age, it would have been just starting to crawl when these stars were born.
Researchers used instruments at the Atacama Large Millimeter/submillimeter Array observatory in Chile to observe light emitted in a galaxy called MACS1149-JD1, one of the farthest light sources visible from Earth. The emissions are a clue to the galaxy’s redshift — a stretching of the wavelength of light that signifies the speed at which an object is moving away from an observer. Scientists can use redshift to estimate how far away (and by extension, how old) a celestial object is.
The galaxy’s redshift suggests that the starlight was emitted when the universe was about 550 million years old, researchers