"If, say, one per cent of red dwarfs have an Earth-like planet around them, this one percent now applies to a number that is three times larger than we had so far assumed."
This photo taken by the Hubble Space Telescope shows a cluster of diverse galaxies / AP Source: AP
THE Universe might hold three times as many stars as was previously thought, a new cosmic census of eight galaxies beyond the Milky Way suggested.
US astronomers said that they discovered that small, dim stars known as red dwarfs are more plentiful than previously estimated.
"A best guess at the total number of stars in the universe is about 100 sextillion -- that is, a '1' followed by 23 zeros. We now believe this estimate is perhaps too low by a factor of about three," said Dr Pieter van Dokkum, of Yale University, who led the research.
Even that estimate remains uncertain, he added, because scientists do not know with confidence how many galaxies there are in the universe.
The findings, published in the journal Nature, also boosted the potential for other planets.
"There are possibly trillions of Earths orbiting these stars," Dr van Dokkum said.
The revised estimate of 300 sextillion stars in the universe emerged from a study of eight elliptical galaxies that are between 50 million and 300 million light years away.
In previous observations of the galaxies, it was impossible to detect red dwarf stars, as they are only about one-tenth of the mass of the sun and 1000 times fainter.
Powerful new instruments at the Keck Observatory in Hawaii allowed Dr van Dokkum's team to work out that the proportion of red dwarfs in elliptical galaxies is about 20 times greater than in the Milky Way.
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