Clear images showing how planets form around young stars

In this series, astronomer Raphael Batchelor reveals to us the most amazing phenomena of the universe. Vibrant research topics, astronomical adventures and scientific news about the universe are analyzed in depth.

Using European telescopes in Chile, excellent images were captured of the formation of planetary systems around 86 very young stars. This data reveals how planets form in different regions of the Milky Way.

diversity

The more than 5,000 planets already identified orbiting stars other than the Sun offer us many surprises. On the one hand, almost all types of stars appear to be capable of having a planetary system, and, moreover, these systems offer enormous diversity; In fact, many known planets are radically different from our solar system. Understanding the source of this diversity is a priority goal for the large community of astronomers today devoted to the study of stars and planets.

The keys to this great diversity of mature planetary systems must be sought by identifying and studying planetary systems in their early stages of formation. This means you have to explore the large disks of dusty gas that still surround young stars. This is exactly what a large international group of astronomers led by Christian Jenske (University of Galway, Ireland), Antonio Garofi (National Institute of Astrophysics, Italy) and Per Gunnar Vallegaard (Anton Pannekoek Institute for Astronomy, Netherlands) have been doing. .

Taurus, Chameleon and Orion

The team studied 86 stars in three of the star-forming regions closest to Earth, those in the constellations Taurus and Chameleon (both about 600 light-years away) and Orion (1,600 light-years away). The observations were made using one of the large VLT telescopes installed by the European Southern Hemisphere Observatory (ESO, of which Spain is a partner) in the Atacama Desert in Chile.

Protoplanetary disks can have sizes much larger than the distance between Earth and the Sun, but the distance at which they are located makes them appear as very small dots in the sky. For detailed observations, the team used a highly sophisticated instrument called SPHERE (Spectral and Polarization High Variance Exoplanet Research), which is equipped with an advanced adaptive optics system that corrects for distortion effects caused by atmospheric turbulence. It also includes a coronagraph that protects the stars themselves, so they are not visible in images. Thanks to this amazing tool, the disc structures and shapes can be clearly seen.

The images show a wide range of structures: concentric rings, large spirals, and other irregular shapes. Naturally, these geometric patterns are determined by the movement of the planets that form them. The rings are separated by apparently empty grooves, which were probably removed after the formation of a protoplanet.

development

Thanks to the large sample of stars observed, astronomers have also reached some statistical conclusions. For example, double or multiple stars are unlikely to maintain a planet-forming disk. On the other hand, Orion's region has the potential to form stars much larger than those of Taurus and Chameleon, and now we can study whether there are also differences in planetary systems.

The difference in stellar masses appears to be why Orion's disks have much more heterogeneous structures; More massive stars are likely surrounded by more massive disks in which larger planets are born. These larger planets will be more capable of distorting and warping disks, phenomena that are less evident in Taurus and Chameleon clouds where stars are low in mass: similar to those in our Sun.

Beyond the beauty of these images, we must take into account the high value of these data for reconstructing the complex physical and chemical processes that lead from an initially poorly structured disk of gas and dust to the formation of a fully formed planetary system. .Organized like the solar system in which the appropriate conditions exist for the emergence of life.

The results of this study were published in three articles in the prestigious European Journal Astronomy and astrophysics Which the authors carry to Jinski et al., Jarofi et al. And Valegaard et al..

Rafael Batchelor is director National Astronomical Observatory (National Geographic Institute) and academic Royal Academy of Physicians of Spain.