Unique, darkish astrophysical objects could also be hiding in interstellar area, and a brand new proposal outlines how you can discover them: stare actually, actually laborious.
We do not know what darkish matter is, though we strongly suspect it exists. We see circumstantial proof for it all over the place, from the rotation charges of galaxies to the expansion of the most important constructions within the cosmos. For many years, cosmologists have thought darkish matter is a few form of unique particle that was beforehand unknown to the Customary Mannequin of particle physics. This unusual particle wouldn’t work together with mild, or actually a lot of anything, besides by means of its gravitational affect.
It could be that dark matter isn’t made of zillions of tiny particles flying through the universe. Instead, it could be composed of bunched-up collections of much larger objects. In particular, the researchers behind a new study, published in November 2025 in the open access server arXiv, investigated two sorts of unique objects.
The primary is named a boson star. On this mannequin, darkish matter is product of an ultra-ultra-ultra mild particle — doubtlessly thousands and thousands of instances lighter than neutrinos, the lightest identified particles. They’d be so mild that their quantum nature would make them seem extra like waves at galactic scales than like particular person particles. However these waves would typically bunch up and accumulate on themselves, pulling along with their very own gravity, with out collapsing.
One other risk is known as Q-balls. On this mannequin, darkish matter is not a particle in any respect however moderately a quantum discipline that soaks all of area and time. On account of a particular property of this discipline, it may sometimes pinch off, creating gigantic, steady, lump-like balls that wander the cosmos like a floating piece of flour in gravy that hasn’t been blended effectively.
Each boson stars and Q-balls, which stay beneath the extra common heading of unique astrophysical darkish objects (EADOs), are tough to detect. They’re massive — roughly star-size — however they don’t emit mild of their very own, making them almost invisible in our scans of the cosmos.
However astronomers have found a means that EADOs can betray their presence: microlensing. If a Q-ball or boson star had been to cross between us and a distant star, the robust gravity of the EADO would trigger the sunshine from the star to behave as a gravitational lens. From our perspective, it will make the star seem to all of a sudden soar into place after which shortly return to regular.
So all we would need to do is stare at an entire bunch of stars for a extremely very long time and hope we get fortunate. Fortunately, we have now simply the instrument for the job. The Gaia area telescope‘s mission was to do exactly that: stare at an entire bunch of stars for a extremely very long time.
The astronomers behind the examine suggest a marketing campaign utilizing Gaia knowledge to seek for Q-balls and boson stars by in search of their distinctive, “smoking gun” sign of sudden jumps in stellar positions. Relying on what number of are on the market, Gaia might have noticed as much as a number of thousand EADOs.
But when they are not on the market, then this identical marketing campaign would produce stringent limits on Q-balls’ and boson stars’ contributions to the general darkish matter image. It doesn’t matter what, staring into the darkish would train us one thing.
