A young gas giant and hidden substructures in a protoplanetary disk
The detection of planets in protoplanetary disks has proven to be extremely challenging. By contrast, rings and gaps, usually attributed to planet-disk interactions, have been found in virtually every large protoplanetary (Class II) disk observed at 0.9-1.3 mm with sufficient spatial resolution (5 au). The nearby disk around MP Mus (PDS 66) stands as an exception to this rule, and its advanced age (7-10 Myr) is particularly difficult to reconcile with its apparent lack of substructures. Despite the disk's smooth appearance, Gaia data of MP Mus show a significant proper motion anomaly, signalling the presence of a companion. Here we present ALMA 3-mm observations of the system with high spatial resolution comparable to previous 1.3-mm data. The new observations pierce deeper into the disk midplane and reveal an inner cavity (<3 au) and a ring at 10 au. The disk structure inferred from ALMA observations narrows down the properties of the companion to a gas giant orbiting at 1-3 au, and hydrodynamic simulations further confirm that such a planet can produce the observed cavity. These independent pieces of evidence constitute an indirect but compelling detection of an exoplanet within a protoplanetary disk using Gaia astrometry. The detection of dust substructures in MP Mus, thanks to the lower optical depths at longer wavelengths, suggests that rings and gaps are even more abundant than previously thought.
Authors
- John M. Carpenter (ORCID: https://orcid.org/0000-0003-2251-0602)
- I. de Gregorio‐Monsalvo (ORCID: https://orcid.org/0000-0003-4518-407X)
- Álvaro Ribas (ORCID: https://orcid.org/0000-0003-3133-3580)
- Enrique Macías (ORCID: https://orcid.org/0000-0003-1283-6262)
- Nicolás Cuello (ORCID: https://orcid.org/0000-0003-3713-8073)
- Sebastián Pérez (ORCID: https://orcid.org/0000-0003-2953-755X)
- C. J. Clarke (ORCID: https://orcid.org/0000-0003-4288-0248)
- Francesco Zagaria (ORCID: https://orcid.org/0000-0001-6417-7380)
- Miguel Vioque (ORCID: https://orcid.org/0000-0002-4147-3846)
- Cristiano Longarini (ORCID: https://orcid.org/0000-0003-4663-0318)
Institutions
- Universidad de Santiago de Chile (CL)
- Centre National de la Recherche Scientifique (FR)
- European Southern Observatory (DE)
- University of Cambridge (GB)
- Atacama Large Millimeter Submillimeter Array (CL)
- Millennium Science Initiative (CL)
- Millennium Institute of Astrophysics (CL)
- Max Planck Institute for Astronomy (DE)
- Millennium Nucleus of Ion Channel Associated Diseases (CL)
- European Southern Observatory (CL)
- Université Grenoble Alpes (FR)
Publication Details
- Journal
- Nature Astronomy
- Published
- 2025-07-14
- DOI
- https://doi.org/10.1038/s41550-025-02576-w
- Citations
- 6
- Primary Topic
- Astrophysics and Star Formation Studies
- Type
- article
- Field-Weighted Citation Impact
- 6.93
Funders
- National Science Foundation
- National Radio Astronomy Observatory
- European Commission
- Korea Astronomy and Space Science Institute
- National Astronomical Observatory of Japan
- Agencia Nacional de Investigación y Desarrollo
- HORIZON EUROPE Framework Programme
- Science and Technology Facilities Council
- National Institutes of Natural Sciences
- Agencia Estatal de Investigación