More planets and stars?

09 April 2009

New research from LJMU astronomers, published in Nature magazine, reveals there may be many more planets and stars in the Universe than previously thought.

Researchers at LJMU have discovered nine billion year old galaxies which are five times larger than they expected to find, throwing doubt on the current theory of how planets and stars form.

The conventional view is that stars and planets are created by hierarchical merging – meaning they are formed gradually over time through gravitational pull.

However, the galaxies found by LJMU astronomers at the Astrophysics Research Institute are relatively young, dating back two thirds of the way to the Big Bang, and yet are fairly substantial in size. With not much time passing to allow the formation of such large galaxies, LJMU’s research suggests they are more likely to have formed during one single, catastrophic event. This secondary theory, known as monolithic collapse, was a popular concept in the 1960s but has, until now, been ruled out by the majority of astronomers.

LJMU's Professor of Cosmology, Chris Collins, explained: "By analysing the light from these remote galaxies, we have effectively weighed them. They are nine billion years old but as the Big Bang took place 13.7 billion years ago, they are relatively young and we would have expected them to be much smaller, around a fifth of the size.

"The findings therefore suggest a different picture in galaxy formation and surprisingly reveal that galaxies may be older than we thought. If they are not formed by gravitational pull, which requires more time, then there could not only be many more galaxies than we think but also more stars and planets."

For more information see http://www.astro.ljmu.ac.uk/