PREVIEW

A European team of astronomers have unveiled a groundbreaking exploration into the intricate process of planet formation through an extensive survey of planet-forming discs.
Using the European Southern Observatory's Very Large Telescope (ESO’s VLT) in Chile, the team captured stunning images in one of the largest-ever surveys of such discs. The research, detailed in three papers published in Astronomy & Astrophysics, focuses on over 80 young stars where planets might be taking shape, offering unprecedented insights into planetary development across diverse regions of our galaxy.
Christian Ginski, lead author and lecturer at the University of Galway, says: “This is really a shift in our field of study. We’ve gone from the intense study of individual star systems to this huge overview of entire star-forming regions.”
To date more than 5000 planets have been discovered orbiting stars other than the Sun, often within systems markedly different from our own Solar System. To understand where and how this diversity arises, astronomers must observe the dust- and gas-rich discs that envelop young stars — the very cradles of planet formation.
To achieve this, the study encompassed 86 stars in three different galactic areas: Taurus, Chamaeleon I, and Orion, each providing distinct perspectives on the planet-forming process.
Ginski adds: “Some of these discs show huge spiral arms, presumably driven by the intricate ballet of orbiting planets.”
The observations, conducted by an international team spanning over 10 countries, used the Spectro-Polarimetric High-contrast Exoplanet REsearch instrument (SPHERE) on ESO’s VLT. This advanced instrument, equipped with extreme adaptive optics, allowed the team to obtain crisp images of the discs, even around stars with half the mass of the Sun.
The findings are rich with insights, such as the revelation in the Orion region that stars in groups of two or more are less likely to possess large planet-forming discs. The uneven appearance of these discs hints at the potential presence of massive planets causing warping and misalignment.
The research, a testament to technological advancements, utilized the Atacama Large Millimeter/submillimeter Array (ALMA) and the VLT’s X-shooter instrument to gather additional data on dust amounts and star characteristics. As technology evolves, the team anticipates using ESO’s forthcoming Extremely Large Telescope (ELT) to explore even deeper into the heart of planet-forming systems.
Per-Gunnar Valegård, who led the Orion study, concludes: “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.”