Astronomers have identified the first ‘sibling’ of the sun, a star born from the same gas cloud and dust of Earth’s star. Stars are born in ‘stellar nurseries’, in huge litters, with many being born at once.
A team of researchers at University of Texas with renowned astronomer Ivan Ramirez are now investigating other ‘solar siblings’ in order to attain a wider understanding of the where and how our sun formed. It will also examine how our solar system became amenable for life.
There is also a ‘small, but not zero’ chance that some of these solar siblings could shelter life. Ramirez explains, “In the earliest days within their birth cluster, collisions could have knocked chunks off of planets and these fragments could have travelled between solar systems, perhaps even may have been responsible for bringing primitive life to Earth.
Fragments from Earth could also have transported life to planets orbiting solar siblings. So it could be argued that solar siblings are key candidates in the search for extra-terrestrial life.”
The sibling’s technical name is HD 162826, is 15% more massive than our sun and positioned 110 light-years away from the constellation Hercules. Ramirez’s team identified HD 162826 out of 30 other candidates, found by several groups worldwide who were observing the sky for solar siblings. Of these, 23 stars were studied at the Harlan J. Smith telescope at McDonald observatory in Texas, USA.
The remaining candidates were only visible from the Southern Hemisphere through the Clay Magellan Telescope at Las Campanas Observatory in Chile. Both telescopes used high-resolution spectroscopy in order to obtain a deep understanding of the stars’ chemical composition.
Each star-forming molecular cloud has its own chemical DNA and if you find a star with the same DNA, you have found it’s respective sibling.
In order to accurately identify a solar sibling, the scientists also need information on the stars’ orbit, where they had previously been, their paths around the centre of the Milky Way and where they are predicted to go in the future. Amalgamating the stars chemical make up and dynamic properties, the candidate siblings was narrowed to HD 162826.
It comes as a great surprise that the astronomers have found even one solar sibling. The sun’s brothers and sisters could have wandered thousands of light years since their birth, pushed and pulled by gravitational encounters with gas clouds and other stars.
Once the identification of solar siblings becomes a regular occurrence, Astronomers will be closer than ever to knowing how the Sun was formed.