JWST discovers first-ever clues of potential 'dark stars' in the early universe

JWST's observation 

In December 2022, Webb spotted three probable dark star candidates: JADES-GS-z13-0, JADES-GS-z12-0, and JADES-GS-z11-0. 

As per the official release, these objects were first identified as galaxies in data analyzed by the JWST’s Advanced Deep Extragalactic Survey (JADES) team.   

The Webb spectroscopic examination found that the objects formed somewhere between 320 million and 400 million years after the Big Bang  – making them the earliest such type of objects to be ever seen.

“When we look at the James Webb data, there are two competing possibilities for these objects. One is that they are galaxies containing millions of ordinary, population-III stars. The other is that they are dark stars. And believe it or not, one dark star has enough light to compete with an entire galaxy of stars,” Freese added. 

These stars are speculated to be supermassive in size, capable of growing to several million times the mass of our sun and shining up to ten billion times brighter than our sun. 

Mysterious elementary particle behind it

Scientists posit that dark stars could be made up of a new type of elementary particle known as Weakly Interacting Massive Particles. 

According to the study, these discovered particles "annihilate themselves" when they smash into each other. In the process, the particles release heat into collapsing clouds of hydrogen, turning them into brightly dark black stars.

If the existence of these enigmatic dark stars is proven, it may provide insight into the prevalence of massive galaxies in the early universe. Earlier, Webb spotted numerous huge galaxies in the early cosmos, but how they accumulated so much stellar stuff to become so massive remains a mystery. Furthermore, the existence of too many big galaxies does not meet the expectations of the standard cosmological model.

“It’s more likely that something within the standard model needs tuning, because proposing something entirely new, as we did, is always less probable. But if some of these objects that look like early galaxies are actually dark stars, the simulations of galaxy formation agree better with observations,” Freese said. 

This study is published in the Proceedings of the National Academy of Sciences.

Study abstract:

The first generation of stars in the universe is yet to be observed. There are two leading theories for those objects that mark the beginning of the cosmic dawn: hydrogen burning Population III stars and Dark Stars, made of hydrogen and helium but powered by dark matter heating. The latter can grow to become supermassive (M⋆ ∼ 106M⊙) and extremely bright (L ∼ 109L⊙). We show that each of the following three objects—JADES-GS-z13-0, JADES-GS-z12-0, and JADES-GS-z11-0 (at redshifts z ∈ [11, 14])—are consistent with a Supermassive Dark Star interpretation, thus identifying the first Dark Star candidates.