This series of images is a solar system 400 light-years away that researchers have caught in the act of forming. According to lead researcher Theresa Paneque-Carreño: Studying how planets form is difficult because it takes millions of years to form planets. This is a very short time-scale for stars, which live thousands of millions of years, but a very long process for us. What we can do is observe young stars, with disks of gas and dust around them, and try to explain why these disks of material look the way they do. It’s like looking at a crime scene and trying to guess what happened.

The particular crime scene they are observing is Elias 2-27, a star previously observed to be surrounded by a disk of material that had spiral structures. In these new observations,  Paneque-Carreño said: We discovered in 2016 that the Elias 2-27 disk had a different structure from other already studied systems, something not observed in a protoplanetary disk before: two large-scale spiral arms. Gravitational instabilities were a strong possibility, but the origin of these structures remained a mystery and we needed further observations.

Gravitational instabilities occur when the stuff that is doing the gravitational pulling has either too much or too little stuff and doesn’t pull the same way as its surroundings. In this case, they think that instability is a knot of material that will one day be a planet. You saw it here, folks; this is a planet forming.

More Information

NRAO press release

“Spiral Arms and a Massive Dust Disk with non-Keplerian Kinematics: Possible Evidence for Gravitational Instability in the Disk of Elias 2-27,” T. Paneque-Carreño et al., to be published in The Astrophysical Journal (preprint on arxiv.org)

“A dynamical measurement of the disk mass in Elias 2-27,” Benedetta Veronesi et al., to be published in The Astrophysical Journal (preprint on arxiv.org)