Planet-forming disks evolve surprisingly similar

Our solar system probably evolved in the same way as most of the other planetary systems around us. This has been shown by German-Austrian-Dutch research on more than 870 planet-forming disks in the Orion Cloud A. The project made use of SURF's data-processing infrastructure.
Planeetvormende schijven rond jonge sterren

This artistic impression illustrates what planet-forming disks around young stars often look like. Initially, they consist of dust and gas that coalesce into rings of dense material. Over time, the solids develop into pebbles that can eventually become planets. (c) MPIA

The older the disk, the less dust

The researchers, led by Dutchman Sierk van Terwisga who now works at the German Max-Planck-Institute for Astronomy, published their findings on Thursday in the journal Astronomy & Astrophysics.

Astronomers have long been searching for the question of whether our solar system is similar to other planetary systems. Until now, astronomers did not know whether there is a decisive factor that determines the evolution of planetary disks around young stars. Now it appears that the mass of a planetary disk actually depends only on its age. The older the disk, the less dust. "At least, this is true if the star and disk are not near harsh environments, such as hot, large stars," says lead researcher Sierk van Terwisga (Max-Planck-Institut für Astronomie, Heidelberg, Germany), "because we excluded those from our study."

The researchers analysed more than 870 planet-forming disks in the molecular cloud Orion A some 1,350 light years away. It is a large, closest star-forming region. The cloud, which is located near the famous Orion Nebula, contains compact clusters of stars similar to those in which our Sun formed. The researchers compared the dust disks in Orion A with other disks in our vicinity.

Only 1 day of computing time thanks to parallel computers

The researchers used data from the Herschel space telescope and from the ALMA observatory. Normally, calibrating or equalising data from ALMA dishes would have taken months. So the team devised a way that allowed them to use SURF's parallel computers. "Our new approach greatly improved the processing speed," says coauthor Raymond Oonk of SURF, Leiden University and ASTRON. "It took 3000 CPU hours to prepare the data for further analysis. On a normal, non-parallel computer that would take 125 days of computing time. With us, thanks to parallel processing, it took only a day."

In the future, the researchers want to see if the planet-forming disks are influenced by small, faint stars that are near them. For their study, the researchers had already eliminated all stars that were in the vicinity of large, hot stars, but small, weak stars could also have an influence.

Planeetvormende schijven

The area that the researchers studied. All the plus signs are planetary disks. The blue dots are discs with more than 100 earth masses. The circle on the right contains the Orion Nebula cluster. It contains large, hot stars that were not included in the study. (c) Van Terwisga et al. / MPIA

Scientific article

Survey of Orion Disks with ALMA (SODA). I: Cloud-level demographics of 873 protoplanetary disks. By: S.E. van Terwisga (1), A. Hacar (2), E.F. van Dishoeck (3,4), R. Oonk (5,3,6) & S. Portegies Zwart (3) In: Astronomy & Astrophysics (2022). Original: | Preprint:

(1) Max-Planck-Institut für Astronomie, Heidelberg, Germany
(2) Department of Astrophysics, University of Vienna, Wenen, Austria
(3) Sterrewacht Leiden, Leiden University
(4) Max-Planck-Institut für Extraterrestrische Physik, Garching bei München, Germany
(5) SURF, Leiden
(6) ASTRON, Dwingeloo

The project was supported by the NWO computing time call through grants EINF 259 and EINF 1290.