Santa Cruz de Tenerife.– An international team of astronomers, with participation from the University of La Laguna (ULL) and the Instituto de Astrofísica de Canarias (IAC), has captured for the first time the details of the “adolescence” of planetary systems, an era that has been surrounded by mystery for a long time.
The study, called ALMA survey to Resolve exoKuiper belt Substructures (ARKS), is based on a series of ten articles that are being published simultaneously in the journal Astronomy and Astrophysics and has been carried out with the Atacama Large Millimeter/submillimeter Array (ALMA).
Thanks to this work, the sharpest images to date of 24 debris disks, the belts of dust that remain after the formation of planets, have been obtained, the IAC reports in a statement.
These disks are the cosmic equivalent of the adolescence of planetary systems: somewhat more developed than planet-forming disks, but without having reached maturity.
According to the IAC, these findings from the ARKS project are very valuable for the search for young planets and the understanding of how they form and reorganize into families, like the planets of the Solar System.
In this sense, Carlos del Burgo, researcher at the ULL and IAC and member of the ARKS project, highlights ALMA’s potential to reveal structures in disks, as it allows increasingly sharper observations that can be combined with radial velocity curves and light curves to improve the characterization of these emerging worlds.
Meredith Hughes, associate professor of astronomy at Wesleyan University (USA) and co-leader of this study, highlights the importance of the project because although photos of the infancy of forming planets have often been seen, until now adolescence was “a missing link”.
The scientist points out that this project allows a new perspective to interpret the craters of the Moon, the dynamics of the Kuiper Belt, and the growth of large and small planets.
The counterpart to this evolutionary phase in the Solar System is the Kuiper Belt, a ring of icy debris beyond Neptune that preserves a record of massive collisions and planetary migrations that occurred billions of years ago.
This new study of 24 exoplanetary debris belts allows for a better understanding of what the Solar System experienced while the Moon was forming and the planets were making their way to their final locations.
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The IAC explains that debris disks are tenuous, hundreds or even thousands of times weaker than the bright, gas-rich disks where planets form.
The ARKS team overcame the challenge to produce images of these disks with unprecedented detail, as these faint disks have managed to hide from astronomers for years but, thanks to ALMA, it is now possible to observe their complex structures.
These are formed by belts with multiple rings, wide and smooth halos, sharp edges and even unexpected arcs and structures.
“We are observing a great diversity: not only simple rings, but belts with multiple rings, halos and strong asymmetries, which reveals a dynamic and complex chapter in planetary history,” adds Sebastián Marino, leader of the ARKS program and associate professor at the University of Exeter (United Kingdom).
The research has made it possible to verify that a third of the observed disks show clear substructures (multiple rings or distinctive gaps) that may have formed in earlier stages of planetary formation or were sculpted by planets over much longer timescales.
While some disks inherit intricate structures, others soften and extend into broad belts, similar to how the Solar System is expected to have developed.
Furthermore, many disks show evidence of calm and chaotic zones, with vertically “inflated” regions, similar to the mixture of classical objects from the solar system’s Kuiper Belt and those scattered by Neptune’s past migration.
It has also been found that several disks retain gas for much longer than expected, and in some systems, the remaining gas can influence the chemical composition of growing planets or even displace dust into wide halos.
The IAC indicates that the ARKS results show that this adolescent stage is a period of transition and turmoil.
The ARKS project is the work of an international team of approximately 60 scientists, led by the University of Exeter, Trinity College Dublin, and Wesleyan University, with the participation of the ULL and the IAC.
