Our Sun's 'Long Lost Brother' Has Planets Too


Astronomers have discovered a star born from the same gas cloud as our sun.

This 'long lost brother' of our star has the slightly less catchy name 'HD 162826'.

The star has its own planets, and astronomers say there is a small but real chance those worlds once hosted life, are habitable right now, or will be one day in the future.

The Sun formed in a massive cloud of gas more than 4.5 billion years ago, along with up to 100,000 other stars.

But gradually those stars broke away from the gas cloud, and were dragged into different orbits around the centre of the galaxy. As a result it is difficult to find stars formed in the same cloud as our own, which obscures elements of our own cosmic origin.

Scientists at the University of Texas at Austin hope that by finding HD 162826 they might be able to locate more stars from the family, and piece together the early history of our solar system.

"We want to know where we were born," said Prof Ramirez, who led the study. "If we can figure out in what part of the galaxy the sun formed, we can constrain conditions on the early solar system. That could help us understand why we are here."

By chance, astronomers at the McDonald Observatory Planet Search team have been studying the same star for years, and know that there are no massive planets orbiting near to the Sun - but there could be smaller, rocky planets further out. Planets like… Earth. The chance is "small, but not zero" that those planets could host life.

The team hopes that new date from the European Space Agency's Gaia telescope will soon make it easy to study more stars and find more analogues to our Sun.

"The number of stars that we can study will increase by a factor of 10,000," Ramirez said.

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