These three objects have been initially recognized as galaxies however they might really be “dark stars”
NASA/ESA
The James Webb Space Telescope (JWST) might have noticed bizarre stars powered by darkish matter as an alternative of nuclear fusion. If these stars are actually on the market, it may remedy three main cosmic mysteries in a single fell swoop.
Regular stars kind when a cloud of mud and gasoline turns into so large that it collapses in on itself, and the stress and temperature within the centre are excessive sufficient to start the method of nuclear fusion, whereby atoms slam collectively and merge into heavier parts. So-called darkish stars wouldn’t have any fusion in any respect – within the early universe, they might kind from related clouds wealthy in darkish matter. For a number of postulated kinds of darkish matter, when two particles collide they need to annihilate in a blast of power, which might be intense sufficient to energy a supermassive star.
“They’re very bizarre stars – in radius they’re around 10 AU [astronomical units, the distance between Earth and the sun], so they’re puffy beasts, and there’s no core,” says Katherine Freese on the University of Texas at Austin. “They’re relatively cool throughout, and because they’re so cool there’s nothing that’s preventing accretion onto them, so they grow – they can grow to a million solar masses, a billion solar luminosities, maybe even more.”
Freese and her colleagues hunted by knowledge on a few of essentially the most distant objects JWST has seen and located three of them that might doubtlessly be supermassive darkish stars, not galaxies as was initially assumed. JWST has discovered many extra distant galaxies than anticipated, which may very well be an issue for our commonplace mannequin of cosmology, so if a few of them are literally darkish stars it may remedy that dilemma.
“Right now the spectra are not really good enough to tell – you’d have to look at one of these objects for a year with JWST, which is not likely to happen,” says Freese. The different option to determine it out can be to discover a darkish star with its mild magnified by gravitational lensing, which may give us way more data.
If these objects end up to actually be darkish stars, it could be a serious leap in our understanding in darkish matter. “Despite decades of experiments and observations, we have yet to conclusively observe anything related to the non-gravitational nature of dark matter,” says Pearl Sandick on the University of Utah. “Observing a dark star would be an incredible confirmation that dark matter experiences forces other than gravity, and at the same time it would really confirm a very interesting and different picture of the formation of the first stars in the universe than the standard story.”
Once a darkish star drifted out of the realm the place it fashioned, it could now not have sufficient darkish matter to behave as gasoline inside it. “As soon as it moves, it’ll collapse, and boom – you have a black hole,” says Freese. But darkish stars can, in concept, develop a lot larger than common stars, so the ensuing black holes can be equally huge. This may present a solution to the long-standing thriller of how supermassive black holes kind within the early universe.
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Source: www.newscientist.com