Forming Planetary Systems That Contain Only Minor Planets
Estimates of the frequency of planetary systems in the Milky Way are observationally limited by the low-mass planet regime. Nevertheless, substantial evidence for systems with undetectably low planetary masses now exist in the form of main-sequence stars which host debris discs, as well as metal-polluted white dwarfs.
Further, low-mass sections of star formation regions impose upper bounds on protoplanetary disc masses, limiting the capacity for terrestrial or larger planets to form. Here, we use planetary population synthesis calculations to investigate the conditions that allow planetary systems to form only minor planets and smaller detritus.
We simulate the accretional, collisional and migratory growth of 1017 kg embryonic seeds and then quantify which configurations with entirely sub-Earth-mass bodies (≲1024 kg) survive. We find that substantial regions of the initial parameter space allow for sub-terrestrial configurations to form, with the success rate most closely tied to the initial dust mass.
Total dust mass budgets of up to 102M⊕ within 10 au can be insufficiently high to form terrestrial or giant planets, resulting in systems with only minor planets.
Consequently, the prevalence of planetary systems throughout the Milky Way might be higher than what is typically assumed, and minor planet-only systems may help inform the currently uncertain correspondence between planet-hosting white dwarfs and metal-polluted white dwarfs.
Forming planetary systems with only sub-Earth-mass minor planets, denoted sub-terrestrial systems. In the top panel, each symbol represents a different planetary system; the coloured shape symbols are the sub-terrestrial systems, and the filled brown circles indicate systems within which at least one surviving body formed with a mass ⩾ 1M⊕. The lower left panel contains the final state of only the sub-terrestrial systems, with the mass of the seeds indicated on the right y-axis, and the lower right panel illustrates the distribution of fg,10 that was used to generate all systems, where MMSN denotes Minimum Mass Solar Nebula. In all cases, q = 1.5, p = 1.0, M⋆ = 1.0M⊕ and τdep = 106.5 yr. — astro-ph.EP
Dimitri Veras, Shigeru Ida
Comments: Accepted for publication in MNRAS
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2409.16354 [astro-ph.EP] (or arXiv:2409.16354v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2409.16354
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Submission history
From: Dimitri Veras
[v1] Tue, 24 Sep 2024 18:00:02 UTC (2,932 KB)
https://arxiv.org/abs/2409.16354
Astrobiology,
