Evidence for the start of planet formation in a young circumstellar disk
Introductory text in journal, 2018

© 2018, The Author(s). The growth of dust grains in protoplanetary disks is a necessary first step towards planet formation1. This growth has been inferred from observations of thermal dust emission2towards mature protoplanetary systems (age >2 million years) with masses that are, on average, similar to Neptune3. In contrast, the majority of confirmed exoplanets are heavier than Neptune4. Given that young protoplanetary disks are more massive than their mature counterparts, this suggests that planet formation starts early, but evidence for grain growth that is spatially and temporally coincident with a massive reservoir in young disks remains scarce. Here, we report observations on a lack of emission of carbon monoxide isotopologues within the inner ~15 au of a very young (age ~100,000 years) disk around the solar-type protostar TMC1A. By using the absence of spatially resolved molecular line emission to infer the gas and dust content of the disk, we conclude that shielding by millimetre-size grains is responsible for the lack of emission. This suggests that grain growth and millimetre-size dust grains can be spatially and temporally coincident with a mass reservoir sufficient for giant planet formation. Hence, planet formation starts during the earliest, embedded phases in the life of young stars.

Author

D. Harsono

Leiden University

Per Bjerkeli

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics, Galactic Astrophysics

M. H. D. van der Wiel

Netherlands Institute for Radio Astronomy (ASTRON)

Jon P Ramsey

University of Copenhagen

Luke T. Maud

Leiden University

L. Kristensen

University of Copenhagen

Jes K. Jørgensen

University of Copenhagen

Nature Astronomy

2397-3366 (eISSN)

Vol. 2 8 646-651

Subject Categories

Astronomy, Astrophysics and Cosmology

Materials Chemistry

Geology

DOI

10.1038/s41550-018-0497-x

More information

Latest update

9/19/2018