A young progenitor for the most common planetary systems in the Galaxy
The Galaxy's most common known planetary systems have several Earth-to-Neptune-size planets in compact orbits<sup>1</sup>. At small orbital separations, larger planets are less common than their smaller counterparts by an order of magnitude. The young star V1298 Tau hosts one such compact planetary system, albeit with four planets that are uncommonly large (5 to 10 Earth radii)<sup>2,3</sup>. The planets form a chain of near-resonances that result in transit-timing variations of several hours. Here we present a multi-year campaign to characterize this system with transit-timing variations, a method insensitive to the intense magnetic activity of the star. Through targeted observations, we first resolved the previously unknown orbital period of the outermost planet. The full 9-year baseline from these and archival data then enabled robust determination of the masses and orbital parameters for all four planets. We find the planets have low, sub-Neptune masses and nearly circular orbits, implying a dynamically tranquil history. Their low masses and large radii indicate that the inner planets underwent a period of rapid cooling immediately after dispersal of the protoplanetary disk. Still, they are much less dense than mature planets of comparable size. We predict the planets will contract to 1.5-4.0 Earth radii and join the population of super-Earths and sub-Neptunes that nature produces in abundance.
Authors
- David Nesvorný (ORCID: https://orcid.org/0000-0002-4547-4301)
- Joe Philip Ninan (ORCID: https://orcid.org/0000-0001-8720-5612)
- Noriharu Watanabe (ORCID: https://orcid.org/0000-0002-7522-8195)
- Andrew W. Mann (ORCID: https://orcid.org/0000-0003-3654-1602)
- Lynne A. Hillenbrand
- Yoichi Tamura (ORCID: https://orcid.org/0000-0003-4807-8117)
- Florence Libotte (ORCID: https://orcid.org/0009-0004-3455-5140)
- Lorenzo Pino (ORCID: https://orcid.org/0000-0002-1321-8856)
- F. Murgas (ORCID: https://orcid.org/0000-0001-9087-1245)
- Ε. Πάλλη (ORCID: https://orcid.org/0000-0003-0987-1593)
- Caleb I. Cañas (ORCID: https://orcid.org/0000-0003-4835-0619)
- Elisabeth Newton (ORCID: https://orcid.org/0000-0003-4150-841X)
- Alessandro A. Trani (ORCID: https://orcid.org/0000-0001-5371-3432)
- James E. Owen (ORCID: https://orcid.org/0000-0002-4856-7837)
- H. Parviainen (ORCID: https://orcid.org/0000-0001-5519-1391)
- Varoujan Gorjian (ORCID: https://orcid.org/0000-0002-8990-2101)
- Néstor Abreu García (ORCID: https://orcid.org/0009-0002-5067-5463)
- Jean-Michel Désert (ORCID: https://orcid.org/0000-0002-0875-8401)
- J. Korth (ORCID: https://orcid.org/0000-0002-0076-6239)
- L. M. Rebull (ORCID: https://orcid.org/0000-0001-6381-515X)
- Erik A. Petigura (ORCID: https://orcid.org/0000-0003-0967-2893)
- Andrew Ridden-Harper (ORCID: https://orcid.org/0000-0002-5425-2655)
- John H. Livingston (ORCID: https://orcid.org/0000-0002-4881-3620)
- Andrew Vanderburg (ORCID: https://orcid.org/0000-0001-7246-5438)
- Jerome de Leon (ORCID: https://orcid.org/0000-0002-6424-3410)
- Kai Ikuta (ORCID: https://orcid.org/0000-0002-5978-057X)
- David R. Ciardi (ORCID: https://orcid.org/0000-0002-5741-3047)
- Konstantin Batygin (ORCID: https://orcid.org/0000-0002-7094-7908)
- Norio Narita (ORCID: https://orcid.org/0000-0001-8511-2981)
- Suvrath Mahadevan (ORCID: https://orcid.org/0000-0001-9596-7983)
- Trevor J. David (ORCID: https://orcid.org/0000-0001-6534-6246)
- Kamen Todorov (ORCID: https://orcid.org/0000-0002-9276-8118)
- Allyson Bieryla (ORCID: https://orcid.org/0000-0001-6637-5401)
- Pedro Pablo Meni Gallardo (ORCID: https://orcid.org/0009-0001-7943-0075)
- M. Mori (ORCID: https://orcid.org/0000-0003-1368-6593)
- Atsunori Yonehara (ORCID: https://orcid.org/0000-0003-3480-0973)
- J. Orell Miquel
- Kento Masuda
- GuÐmundur Stefánsson
- Akihiko Fukui
- Jesus Higuera
- Eric E. Mamajek
Institutions
- Dartmouth College (US)
- University of North Carolina at Chapel Hill (US)
- University of Geneva (CH)
- Tata Institute of Fundamental Research (IN)
- California Institute of Technology (US)
- Las Cumbres Observatory Global Telescope Network (US)
- Southwest Research Institute (US)
- Planetary Science Institute (US)
- Goddard Space Flight Center (US)
- Pennsylvania State University (US)
- University of North Carolina Health Care (US)
- Jet Propulsion Laboratory (US)
- Tokyo University of Science (JP)
- University of California, Los Angeles (US)
- Kyoto Sangyo University (JP)
- The Graduate University for Advanced Studies, SOKENDAI (JP)
- Arcetri Astrophysical Observatory (IT)
- NASA Exoplanet Science Institute (US)
- International School of Trieste (IT)
- Osaka Health Science University (JP)
- Astrobiology Center (JP)
- Center for Astrophysics Harvard & Smithsonian (US)
- Hospital de Sabadell (ES)
- Instituto de Astrofísica de Canarias (ES)
- NSF NOIRLab (US)
- Niels Brock (DK)
- Flatiron Health (United States) (US)
- National Astronomical Observatory of Japan (JP)
- Imperial College London (GB)
- Massachusetts Institute of Technology (US)
- The University of Tokyo (JP)
- University of Amsterdam (NL)
- The University of Osaka (JP)
Publication Details
- Journal
- Nature
- Published
- 2026-01-07
- DOI
- https://doi.org/10.1038/s41586-025-09840-z
- Citations
- 4
- Primary Topic
- Stellar, planetary, and galactic studies
- Type
- article
- Field-Weighted Citation Impact
- 95.30
Funders
- National Science Foundation
- National Aeronautics and Space Administration
- W. M. Keck Foundation
- Purdue University
- California Institute of Technology
- University of Wisconsin-Madison
- Space Telescope Science Institute
- Jet Propulsion Laboratory
- Science Mission Directorate
- NASA Headquarters
- Japan Society for the Promotion of Science
- Precursory Research for Embryonic Science and Technology