Deep in its searing sizzling stomach, the large crimson star Betelgeuse may very well be producing tons of hypothetical darkish matter particles referred to as axions that, in the event that they exist, would give off a telltale sign. A current seek for such a tantalizing emission has turned up empty, however helps physicists place new limits on the putative axion’s properties.
Showing as a brilliant crimson dot within the constellation Orion, Betelgeuse is a well-studied star. It’s cosmologically shut, being solely 520 light-years from Earth, and made headlines final 12 months when it began mysteriously dimming, main some researchers to consider it may very well be making ready to blow up as a supernova.
As a result of it’s such a big and sizzling star, Betelgeuse may additionally be an ideal place to seek out axions, scientists say. These conjectured particles may have maybe a millionth or perhaps a billionth the mass of an electron and are excellent candidates to make up darkish matter, the mysterious substance vastly outweighing atypical matter within the universe however whose nature continues to be largely undetermined.
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As darkish matter, axions shouldn’t work together a lot with luminous particles, however in line with some theories, there’s a small likelihood that photons, or mild particles, may convert forwards and backwards into axions within the presence of a powerful magnetic discipline, Mengjiao Xiao, a physicist on the Massachusetts Institute of Know-how (MIT) in Cambridge, advised Dwell Science.
The thermonuclear core of a star is an efficient place to seek out copious quantities of each photons and magnetism, and Betelgeuse, which has 20 occasions the mass of the solar, may conceivably be “what we name an axion manufacturing unit,” he mentioned.
If axions are produced on this excessive atmosphere, they need to have the ability to escape outwards and stream in direction of Earth in giant numbers. By interacting with the Milky Approach galaxy’s pure magnetic discipline, these axions may very well be transformed again into photons within the X-ray a part of the electromagnetic spectrum, Xiao mentioned.
As an aged star, Betelgeuse is in a life stage the place it shouldn’t be emitting a lot X-ray mild, he added, so any such radiation detected from it would point out the presence of axions.
Xiao and his colleagues used NASA’s space-based Nuclear Spectroscopic Telescope Array (NuSTAR) to hunt for an X-ray signature coming from Betelgeuse, although they noticed nothing past what was anticipated from atypical astrophysical processes such because the small quantity of X-rays that Betegeuse is making. Their findings, which Xiao will current on April 20 on the American Bodily Society’s April assembly, recommend that photons and axions are at the very least thrice much less prone to work together than beforehand believed.
As a result of stellar environments are a lot noisier than circumstances present in a lab, doing searches akin to this are tough, mentioned Joshua Foster, a physicist at MIT who was not concerned within the work however who has been a part of an effort to search for axions coming from the star clusters close to our galaxy’s heart. However the staff labored onerous to quantify their uncertainties and helped put new constraints on the axion’s potential properties, Foster advised Dwell Science.
Even when researchers noticed surprising X-rays coming from a star, it wouldn’t essentially point out that axions are actual. Scientists would nonetheless need to rule out many non-dark-matter explanations for the sign earlier than turning to new physics, Foster mentioned.
However it’s potential that axions, ought to they at some point be discovered, may assist astronomers higher perceive Betelgeuse, Xiao mentioned. If the particles’ properties had been recognized, telescopes educated on Betelgeuse would possibly have the ability to lastly decide up their sign, giving insights into processes taking place in its stomach and enabling researchers to calculate when it would really explode, he added.
Initially printed on Dwell Science.