The disk with three rings making metal-rich planets

The colors correspond to the following wavelengths : blue : 2.2 um, green : 4.75 um, red : 11.3 um. Note that the central star is not shown in this image.
Why are those rings important? In most cases, extrasolar planets (outside of our Solar System) are too small and faint to be detected directly. However sufficiently massive planets, already present in the protoplanetary disk, clear gaps along their orbits. Thus, the ringed structure of the HD 144432 disk hints at the potential presence of unseen planets.
In addition, the astronomers studied the material composition of the dust in the disk, and there they found the most abundant building blocks that make up the core and mantle of Earth: magnesium, silicon, oxygen, and indications for an abundant presence of iron. So far, iron has only been suspected to be present in the inner disk regions. Remarkably, the new analysis prefers iron-rich and carbon-poor building blocks, which is similar to what we had on Earth. These results suggest that the chemical composition of Earth and other Solar System planets is not exceptional but may be fairly common in our Galaxy.
The research is led by Dr. József Varga at the Konkoly Observatory, Budapest, Hungary. The research team is built around the VLTI/MATISSE and VLTI/GRAVITY instrument consortia, with the participation of colleagues from French, German, Dutch and Hungarian institutes, among others.
VLTI combines the light of four telescopes to obtain a virtual telescope with an effective diameter of about 130 m, which makes possible to resolve the details of a planet forming disk on a scale of a few milliarcseconds (a millionth of the apparent size of the Moon on the sky). While single existing 10-m telescopes would only give a blurry picture of the disk without any details, the so-called interferometric technique gives a huge boost in detail. As an example, with the VLTI’s resolution one could count the spots of a ladybug from 40 km (25 miles) afar.


Credit : J.L. Dauvergne & G. Hüdepohl (atacamaphoto.com)/ESO
Reference
J. Varga, L.B.F.M. Waters, M. Hogerheijde & al. Mid-infrared evidence for iron-rich dust in the multi-ringed inner disk of HD 144432 Astronomy & Astrophysics, 2024 January 8th DOI 10.1051/0004-6361/202347535
Contacts scientifiques locaux
- Karine Perraut - Astronomer UGA at the Observatoire des sciences de l’Univers de Grenoble, attached to IPAG, a laboratory member of the OSUG federation
- Jean-Charles Augereau - Astronomer UGA at the Observatoire des sciences de l’Univers de Grenoble, attached to IPAG, a laboratory member of the OSUG federation
Updated on 10 January 2024