In the big image at left, the many galaxies of a massive cluster called MACS J1149+2223 dominate the scene. Gravitational lensing by the giant cluster brightened the light from the newfound galaxy, known as MACS 1149-JD, some 15 times. At upper right, a partial zoom-in shows MACS 1149-JD in more detail, and a deeper zoom appears to the lower right. (NASA/ESA/STScI/JHU)

Astronomers Confirm Second Most-Distant Galaxy Ever, And Its Stars Are Already Old

Even before we have the James Webb Space Telescope, a controversy over when the first stars formed is growing.

As far back as our most powerful telescopes have ever looked, we’ve never yet found the limit of where stars and galaxies cease to exist. There’s a big gap between the first galaxy we’ve ever found — GN-z11, from when the Universe was only 400 million years old — and the Big Bang’s leftover glow, from when the Universe was 380,000 years old. In between, we know the first stars must be there, but we don’t have the capabilities to directly see in that range. Until we get the James Webb Space Telescope, we’ll only have indirect evidence to guide us.

As we’re exploring more and more of the Universe, we’re able to look farther away in space, which equates to farther back in time. The James Webb Space Telescope will take us to depths, directly, that our present-day observing facilities cannot match. (NASA / JWST and HST teams)

But as far as indirect evidence goes, we just got a huge boost. Scientists have just confirmed the second most distant galaxy of all: MACS1149-JD1, whose light comes from when the Universe was 530 million years old: less than 4% of its present age. But what’s remarkable is that we’ve been able to detect oxygen in there, marking the first time we’ve seen this heavy element so far back. From…