ALMA | NRAO | 2020 Sep 03
Using the Atacama Large Millimeter/submillimeter Array (ALMA), two teams of astronomers have for the first time discovered a planet-forming disk with misaligned rings around a triple star system, called GW Orionis. The astronomers give two possible scenarios for the misalignment: either the disk was torn apart by the gravitational pull from the stars, or by a newborn planet.
Most stars that look like our Sun are born with siblings. Unlike the planets in our Solar System, which all orbit in the same plane around the Sun, planets around these multi-star systems often have orbits that are not aligned with the orbits of their stars. Their crooked orbits originate in the planet-forming disks, the birthplaces of planets. Studying misaligned disks around multiple stars therefore helps us understand how these planets form (Previously ALMA imaged the misaligned disks in the ‘Tatooine’ binary star system).
In a new study, two independent teams of astronomers pointed ALMA at GW Orionis. This is a young star system hosting three stars. The inner stars GW Ori A and B orbit each other and are separated by 1 au, and the third star GW Ori C orbits its two siblings at a distance of roughly 8 au.
ALMA found three separate rings with different orientations in the massive planet-forming disk of GW Orionis, located roughly 46, 185, and 340 au from its center. The inner ring is very misaligned relative to both the outer rings and the three stars. The outermost ring is the largest ever observed in planet-forming disks. If a planet would be forming in the gap between the inner and outer ring, it would be located incredibly far away from the stars. For comparison, Neptune is only about 30 au from the Sun. ...
New Observations Show Planet-Forming Disc Torn Apart by its Three Central Stars
ESO Science Release | VLTI | ALMA | 2020 Sep 03
Peculiar Planetary System Architecture Around Three Orion Stars Explained
Carnegie Institution for Science | 2020 Sep 03
Misaligned Planet-Forming Rings Around Triple Young Stars
National Astronomical Observatory of Japan | 2020 Sep 04
A Triple Star System with a Misaligned and Warped Circumstellar Disk Shaped by Disk Tearing ~ Stefan Kraus et al
- Science 369(6508):1223 (04 Sep 2020) DOI: 10.1126/science.aba4633
- arXiv.org > astro-ph > arXiv:2004.01204 > 02 Apr 2020
- Astrophysical Journal Letters 895(1):L18 (2020 May 20) DOI: 10.3847/2041-8213/ab8eb4
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