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Pebble-driven planet formation around very low-mass stars and brown dwarfs

Liu, Beibei LU orcid ; Lambrechts, Michiel LU ; Johansen, Anders LU ; Pascucci, Ilaria and Henning, Thomas (2020) In Astronomy and Astrophysics 638.
Abstract

We conduct a pebble-driven planet population synthesis study to investigate the formation of planets around very low-mass stars and brown dwarfs in the (sub)stellar mass range between 0.01 M- and 0.1 M-. Based on the extrapolation of numerical simulations of planetesimal formation by the streaming instability, we obtain the characteristic mass of the planetesimals and the initial mass of the protoplanet (largest body from the planetesimal populations), in either the early self-gravitating phase or the later non-self-gravitating phase of the protoplanetary disk evolution. We find that the initial protoplanets form with masses that increase with host mass and orbital distance, and decrease with age. Around late M-dwarfs of 0.1 M-, these... (More)

We conduct a pebble-driven planet population synthesis study to investigate the formation of planets around very low-mass stars and brown dwarfs in the (sub)stellar mass range between 0.01 M- and 0.1 M-. Based on the extrapolation of numerical simulations of planetesimal formation by the streaming instability, we obtain the characteristic mass of the planetesimals and the initial mass of the protoplanet (largest body from the planetesimal populations), in either the early self-gravitating phase or the later non-self-gravitating phase of the protoplanetary disk evolution. We find that the initial protoplanets form with masses that increase with host mass and orbital distance, and decrease with age. Around late M-dwarfs of 0.1 M-, these protoplanets can grow up to Earth-mass planets by pebble accretion. However, around brown dwarfs of 0.01 M-, planets do not grow to the masses that are greater than Mars when the initial protoplanets are born early in self-gravitating disks, and their growth stalls at around 0.01 Earth-mass when they are born late in non-self-gravitating disks. Around these low-mass stars and brown dwarfs we find no channel for gas giant planet formation because the solid cores remain too small. When the initial protoplanets form only at the water-ice line, the final planets typically have 15% water mass fraction. Alternatively, when the initial protoplanets form log-uniformly distributed over the entire protoplanetary disk, the final planets are either very water rich (water mass fraction 15%) or entirely rocky (water mass fraction 5%).

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Please use this url to cite or link to this publication:
author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Methods: numerical, Planets and satellites: formation
in
Astronomy and Astrophysics
volume
638
article number
A88
publisher
EDP Sciences
external identifiers
  • scopus:85087913685
ISSN
0004-6361
DOI
10.1051/0004-6361/202037720
language
English
LU publication?
yes
id
44c97e58-f8db-4321-93ac-ace7777feb9c
date added to LUP
2020-07-30 08:44:57
date last changed
2024-03-20 13:25:18
@article{44c97e58-f8db-4321-93ac-ace7777feb9c,
  abstract     = {{<p>We conduct a pebble-driven planet population synthesis study to investigate the formation of planets around very low-mass stars and brown dwarfs in the (sub)stellar mass range between 0.01 M- and 0.1 M-. Based on the extrapolation of numerical simulations of planetesimal formation by the streaming instability, we obtain the characteristic mass of the planetesimals and the initial mass of the protoplanet (largest body from the planetesimal populations), in either the early self-gravitating phase or the later non-self-gravitating phase of the protoplanetary disk evolution. We find that the initial protoplanets form with masses that increase with host mass and orbital distance, and decrease with age. Around late M-dwarfs of 0.1 M-, these protoplanets can grow up to Earth-mass planets by pebble accretion. However, around brown dwarfs of 0.01 M-, planets do not grow to the masses that are greater than Mars when the initial protoplanets are born early in self-gravitating disks, and their growth stalls at around 0.01 Earth-mass when they are born late in non-self-gravitating disks. Around these low-mass stars and brown dwarfs we find no channel for gas giant planet formation because the solid cores remain too small. When the initial protoplanets form only at the water-ice line, the final planets typically have 15% water mass fraction. Alternatively, when the initial protoplanets form log-uniformly distributed over the entire protoplanetary disk, the final planets are either very water rich (water mass fraction 15%) or entirely rocky (water mass fraction 5%). </p>}},
  author       = {{Liu, Beibei and Lambrechts, Michiel and Johansen, Anders and Pascucci, Ilaria and Henning, Thomas}},
  issn         = {{0004-6361}},
  keywords     = {{Methods: numerical; Planets and satellites: formation}},
  language     = {{eng}},
  publisher    = {{EDP Sciences}},
  series       = {{Astronomy and Astrophysics}},
  title        = {{Pebble-driven planet formation around very low-mass stars and brown dwarfs}},
  url          = {{http://dx.doi.org/10.1051/0004-6361/202037720}},
  doi          = {{10.1051/0004-6361/202037720}},
  volume       = {{638}},
  year         = {{2020}},
}