BEIJING, Sept. 14 (Xinhuanet) -- The way stars were formed when the universe was born could be the key to what is dark matter; the mysterious, invisible substance that scientists say makes up more than 25 percent of the cosmos, according to a study published Thursday.

Cosmologists using sophisticated computer simulations at Britain's Durham University concluded that dark matter, which has been divided into both "warm" and "cold" matter, was key to the formation of the stars.

"Dark matter's gravity anchored the nascent starts, but its energy affected how and where they were born," said Joanna Baker, associate editor at Science magazine.

"If the first constellations can be mapped by future telescopes, the energy of the underlying dark matter may be deduced simply by reading the stars, telling us what dark matter is potentially made of."

Durham University's computer model found that in slow-moving "cold dark matter," the first stars appeared in isolation, whereas in the faster-moving "warm dark matter" a burst of a large number of stars occurred in long filaments.

"These filaments would have been around 9,000 light years long, which is about a quarter of the size of the Milky Way galaxy today," said cosmologist Liang Gao. "The very luminous star burst would have lit up the dark universe in spectacular fashion."

Such early stars must still exist in the Milky Way and their discovery could provide vital clues to scientists about the nature of dark matter, which 70 years after its discovery continues to confound the experts.

American astronomers spotted a ring of dark matter in a galaxy cluster in May and said it presented the most solid proof yet of the existence of dark matter.

Astronomers have long suspected there must be some substance holding galaxy clusters together, otherwise galaxies would only have the gravity from their visible stars, which would not be enough to keep them from flying apart.

Astronomers have inferred that dark matter, which is believed to make up more than a quarter of the universe, exists by observing how its gravity bends the light of more distant background galaxies.

(Agencies)