Scientists have discovered that there might be dark matter trapped inside the sun - and it could be  the solar interior. The bold new theory suggests that a form of the mysterious particle - which has yet to be directly observed - is absorbed by the sun from the centre of our galaxy. And once inside, it affects the movement of heat within our solar system's star - which could explain why scientists have struggled to explain 'pressure waves' inside the sun. Durham University scientists have proposed a new model for the sun. They say that dark matter may be transferring heat around its interior (artist's illustration shown). This would help explain how pressure waves move around the sun. Current models are insufficient to account for how they move . The theory was put forward by scientists from Durham University. They propose that so-called asymmetric dark matter (ADM) could explain some inconsistencies in the standard solar model. So far, the standard solar model has proved successful in calculating the sun’s density and temperature - but measuring 'pressure waves' in its interior has proved much more difficult. The sun is about 15 million Kelvin in temperature at its core, and 6,000 Kelvin at its surface. When physicists study the dynamics of galaxies and the movement of stars, they are confronted with a mystery. If they only take visible matter into account, their equations simply don't add up; the elements that can be observed are not sufficient to explain the rotation of objects and the existing gravitational forces. There is something missing. From this they deduced that there must be an invisible kind of matter that does not interact with light but does, as a whole, interact by means of the gravitational force. Called 'dark matter', this substance appears to make up at least 80 per cent of the matter in the known universe. Pressure waves are produced as a result of activity on the solar surface. They are not entirely dissimilar to pressure waves - or P -waves - produced on Earth during an earthquake. It has previously been theorised that dark matter originating from elsewhere in the galaxy may have an affect on the sun - particularly its activity and even its structure. ‘Weakly-interacting dark matter from the galactic halo is captured when it passes through the sun,’ the researchers note in their paper. The dark matter becomes gravitationally trapped within the sun because it does not contain much antimatter. This means it is not destroyed when it interacts with other matter - so the sun likely has a steadily increasing amount of dark matter. And this same dark matter could be having more of an effect on the sun than previously thought. According to the researchers, dark matter (illustration shown) originates in the galactic halo of the Milky Way before passing through the sun - and in some instances, it becomes gravitationally trapped . Dark matter particles are thought to absorb energy in the hottest, central parts of the core. They then travel to different regions of the sun before scattering again and ‘re-depositing their energy,’ the researchers write. This reduces the central temperature and moves heat elsewhere. But this same effect also leads to lower nuclear fusion rates in the core, so the sun compensates by pumping more hydrogen into its core - keeping its luminosity constant. This has an effect of lowering the pressure towards the sun’s surface. 'To prove that this is really what is going on in the sun, we'd need to find a stable dark matter particle that interacts in this way with normal matter,' Dr Pat Scott from the Astrophysics group at  Imperial College London, who was involved in the research, told MailOnline. 'Either the next run of the Large Hadron Collider, or some of the next generation of direct searches for dark matter, should be able to find such a particle if it exists.' Pressure waves in the sun are produced as a result of activity on the solar surface, shown here in this illustration. Red and blue denote different directions for the waves. They are not entirely dissimilar to pressure waves - or P-waves - produced on Earth during an earthquake . ‘The structural changes in the core shift the balance between gravity and pressure elsewhere,’ say the researchers. This would explain why observations of pressure waves in the sun - namely how they move, and how heat is transported - do not match up with theories of solar behaviour. Another conclusions the scientists is that the type of dark matter in the sun is ‘asymmetric,’ as mentioned earlier, which means it contains very little antimatter. ‘The relative absence of antimatter means that the density of the sun’s dark matter is not decreased over time,’ notes Kathy Fey from The Space Reporter. ‘Their model relies on the assumption that it is the change in momentum during particle collisions between dark and normal matter that drive the nature of the interactions between particles. ‘The calculations produced by the team suggest that dark matter displaying this property would transfer large amounts of heat from the sun’s core to its surface.’ The researchers also note that their theory is consistent with predicted properties of dark matter that is being searched for with detectors on Earth and in space.
Durham University scientists have proposed a new model for the sun . They say that dark matter may be transferring heat around its interior . This would help explain how pressure waves move around the sun . Current models are insufficient to account for how they move . The dark matter could be originating in the galactic halo of the Milky Way .