Friday, 03 Oct, 2008 Science

According to a new study, Milky Way presumably has in its center stars that are able to absorb the mysterious dark matter, thus extending their life by not less than a billion years. In case scientists find proof that such stars exist, they will be able to understand what the dark matter is really made of.

Despite the fact that 90 percent of the mass of Milky Way galaxy is composed of dark matter, the latter is too disperse to have a significant impact on stars in the galaxy. However, being close to the huge black hole found at the galactic center, the dark matter could be quite dense, in fact, it could be so dense that stars are able to capture it at high rates.

Having the goal of studying the effects of such stars on dark matter, Pat Scott of Stockholm University in Sweden together with his colleagues came up with the model that shows the development of stars while they gravitationally amassed a group of dark matter particles called WIMP (weakly interacting massive particles).

Researchers found that stars orbiting 0.3 light years away from the center of the galaxy are able to capture weakly interacting massive particles in great quantities. When the particles of dark matter are caught they crash with gas found in the star. After the collision, the particles lose their energy and settle at the center of the star, where they hit each other and wipe out. After the annihilation, the particles of dark matter generate a blast of energy that inflates the star.

Due to this expansion, a star burns its energy at a lower rate. In case the stars had about the mass of our Sun, they would be able to gather enough dark matter to increase their lifetime by a billion years or more.

According to Fabio Iocco of the National Institute for Astrophysics in Firenze, Italy, this particular study features the most detailed estimations on how normal stars capture particles of dark matter.

Igor Moskalenko of Stanford University in California, outlined that in case researchers were able to look through the gas and dust in our galaxy to show that such stars existed, they could discover the first direct proof that dark matter is real.

"If there is even a single star with the predicted properties found there, it will be direct evidence that astrophysical dark matter consists of WIMPs and not something else - a major breakthrough," said Moskalenko.

Source: NewScientist