Where they lived, how big they were, how much light they emitted, whether they even existed, we weren't sure. What we've done, we think, is obtain the first information about these stars.

It took us over a year to convince ourselves that we did [the calculations] well. But we found the same signal at all wavelengths.

We think we are seeing the collective light from millions of the first objects to form in the universe. The objects disappeared eons ago, yet their light is still traveling across the universe.

If these [earliest stars] were very massive and formed in the standard cosmological mode, they should have left a signature in the fluctuations of the CIB. That's the signal we sought to measure with these observations.

For these stars to have produced a signal this strong, they had to be very massive stars, much bigger than what we see in the Universe.

They have basically been theoretical objects.