A team of astronomers have discovered a large number of newborn stars that shed light on the creation of a new solar system.

The international team of scientists, led by Dr Carlos Contreras and Dr Philip Lucas at the University of Hertfordshire, have discovered 816 stars, at least half of which are new.

The new type of stars, which have been called MNors, were discovered while researchers across the globe surveyed around 300 million stars in the Milky Way Galaxy. The team were attempting to solve a long-standing mystery surrounding star formation.

Dr Contreras said: “Stars and planets are known to form in a spinning disc of gas and dust that gradually feeds matter on to the newborn star, or protostar, at the centre.

“This process is hidden from view in visible light for about half a million years. Once this has happened, then the obscuring cloak of matter around a newborn solar system is gathered in or dispersed.”

Over the past 30 years astronomers across the world have seen sudden eruptions of light in about 20 slightly older stars that are approximately 1 million years old. These stars become almost 100 times brighter in visible light. This is because a large amount of matter is suddenly dumped on to the surface of the protostar by the surrounding disc.

Researchers were trying to discover why this sudden change happens when they discovered the newborn stars that cannot usually be seen in visible light. Using an infrared telescope based in Chile, they were able to see through the dust and see the protostars.

The process of surveying more than 300 million stars took the team five years, from 2010 to 2015. They also found that over 100 of the new MNor stars discovered have major eruptions that see them brighten by up to a factor of 40 in outbursts that can last for several years.

The research also shows that these eruptions are far more common in the MNor stars than in the older systems. Around 4 per cent of the protostars that were monitored had an eruption in a space of only four years.

Dr Phil Lucas, from the Centre for Astrophysics Research at Hertfordshire, said: “It still remains to be seen whether most stars are assembled in fits and starts like this, or by a gentle steady accumulation of matter. These discoveries have led to more questions about the nature of this new population of extreme variable stars.”

To shed more light on the nature of these objects the Magellan Telescope in Chile, run by the Carnegie Observatory was used by Dr Kurtev and Dr Borissova. They found that the spectra of the MNors often appeared quite different from previously studied erupting stars. Therefore, the structure of these newborn solar systems is not yet clear.

Dr Kurtev said: “The duration of the outbursts in regular stars is also different when compared to MNors. Previously seen outbursts in visible light either lasted many decades or only about a year, compared to a few years in the new optically hidden MNors. In some MNors the rise and fall seems to be periodic, suggesting that an interaction with a companion star or planet may be responsible.

"This timescale of typically a few years is different but it seems clear that many new solar systems have a bumpy start.”

Dr Lucas added: “This is an exciting discovery that could change the way we think about star formation. It throws up a lot of questions in relation to how stars are born, but this is something we will continue to research.”