In the ongoing search for dark matter in our universe, scientists believe they have found a unique and powerful detector: exoplanets.
In a new article, two astrophysicists suggest dark matter could be detected by measuring its effect on the temperature of exoplanets, which are planets outside our solar system.
This could provide new knowledge about dark matter, the mysterious substance that cannot be observed directly, but makes up about 80% of the mass of the universe.
“We believe there should be around 300 billion exoplanets waiting to be discovered,” said Juri Smirnov, a researcher at the Center for Cosmology and Astroparticle Physics at Ohio State University.
“Even finding and studying a small number of them could give us a lot of information about dark matter that we don’t know now.”
Smirnov co-authored the article with Rebecca Leane, postdoctoral researcher at the SLAC National Accelerator Laboratory at Stanford University. It was published today (April 22, 2021) in the journal Physical examination letters.
Smirnov said that when the gravity of exoplanets captures dark matter, dark matter moves to the planetary core where it “annihilates” and releases its energy in the form of heat. The higher the captured dark matter, the more it should heat the exoplanet.
This heating could be measured by NASA’s James Webb Space Telescope, an infrared telescope scheduled to launch in October and which will be able to measure the temperature of distant exoplanets.
“If exoplanets have this abnormal warming associated with dark matter, we should be able to pick up on it,” Smirnov said.
Exoplanets can be particularly useful for detecting light dark matter, said Smirnov, which is dark matter with lower mass. Researchers have yet to probe light and dark matter by direct detection or other experiments.
Scientists believe that the density of dark matter increases towards the center of our Milky Way galaxy. If this is true, the researchers should find that the closer the planets are to the galactic center, the more their temperatures are expected to rise.
“If we found something like this it would be amazing. Obviously we would have found dark matter,” Smirnov said.
Smirnov and Leane propose a type of research that would involve looking near Earth at gas giants – called “Super Jupiters” – and brown dwarfs for evidence of heating caused by dark matter. An advantage of using planets like this as dark matter detectors is that they do not have nuclear fusion like stars do, so there is less “background heat” which would make searching difficult. of a dark matter signal.
In addition to this local research, the researchers suggest a search for distant rogue exoplanets that are no longer orbiting a star. The absence of radiation from a star would again reduce interference that could obscure a dark matter signal.
One of the best parts about using exoplanets as dark matter detectors is that it doesn’t require any new kind of instrumentation like telescopes or research that isn’t already underway, Smirnov said.
At present, researchers have identified more than 4,300 confirmed exoplanets and 5,695 additional candidates are currently under investigation. Gaia, a space observatory of the European Space Agency, is expected to identify tens of thousands of other potential candidates over the next few years.
“With so many exoplanets studied, we will have a tremendous opportunity to learn more about dark matter than ever before,” said Smirnov.
Source of the story:
Material provided by Ohio State University. Original written by Jeff Grabmeier. Note: Content can be changed for style and length.