In what feels like Christmas for astronomy lovers, a team of researchers has unveiled a close glimpse at more than 80 stars across our galaxy – images that could reveal new insights into how planets are born.
The young stars, imaged using the European Southern Observatory's Very Large Telescope (ESO's VLT) in Chile, are all surrounded by spectacular discs of dust and gas. It's this material that eventually binds together to become planets.
While such discs can span distances hundreds of times greater than the distance between the Earth and Sun, their location hundreds of light-years from us makes them appear as little more than tiny pinpricks in the night sky. As a result, the new images don't show individual planets but hint at the processes that are happening as they form.
The discs in the new images have a diverse range of shapes and sizes, showing the complex variety in how planetary systems can form. Some have huge spiral arms that the researchers think could be driven by planets orbiting around the stars, while others have rings and large cavities in the gas and dust that are carved out as planets form. Meanwhile, some of the discs appear almost completely smooth, like bowls floating through distant space.
“It is almost poetic that the processes that mark the start of the journey towards forming planets and ultimately life in our own Solar System should be so beautiful,” said Per-Gunnar Valegård, a doctoral student at the University of Amsterdam, the Netherlands, who led one of the studies.
It’s previously puzzled astronomers why many of the other solar systems spotted from Earth (over 5,000 so far) appear so different to our own. However, these new images could hint that the discs that surround younger stars may have a role. However, researchers are still unclear as to why discs are so diverse.
In all, the team studied 86 stars across three star-forming regions: Taurus and Chamaeleon I, both roughly 600 light-years away, and Orion, a gas-rich cloud 1600 light-years away from Earth that’s known for birthing massive stars. The observations involved a large international team of scientists spanning more than 10 countries.
Amongst the treasure trove of findings released with the new study, astronomers were able to glean a number of key insights into where and why planets might be forming. For example, they found that stars gravitationally bound in groups of two or more were less likely to have large planet-forming discs. This could be significant as, unlike our Sun, most stars have companions.
The hope is that future telescopes, such as ESO’s upcoming Extremely Large Telescope with its gigantic 39-metre mirror, will allow astronomers to plumb the depths of planet-forming discs like these, revealing in even greater detail the regions close to stars where rocky planets like Earth are forming. We might even witness a young Earth in the process of being born.
"This is a massive shift for our field," said Christian Ginski, a lecturer at the University of Galway, Ireland, and lead author of one of three new papers published in Astronomy & Astrophysics. "We've moved from studying individual star systems to having a vast overview of entire star-forming regions."
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