Work

The size and mass distribution of cold classical TNOs for $5

Year: 2026

Type: preprint

Abstract: The cold classical trans-Neptunian objects (CCs) are the only observable \textit{in situ} population of planetesimal remnants believed to have escaped collisional grinding. Recent JWST observations make it possible to fit the differential absolute magnitude distribution $dN/dH$ of the CCs from $513$ is unwise, as the different analytic forms diverge. It remains unclear if $dN/dH$ turns over at faint $H.$ The uncertainty in the total mass of the CC belt is dominated by uncertainty in the relation between $M$ and $H$. A calibration using CC binaries suggests a total CC mass of 1.7--2.7$\times10^{-3}\,M_\oplus.$ A trend toward lower density and/or higher albedo for smaller bodies may be present in the data, and would lower the estimated total CC mass. Qualitative comparison of the derived mass distribution to the results of numerical simulations of the streaming instability (SI) suggest the simulations produce $dN/dM$ distributions that are more sharply peaked, and steeper at the bright end, than the CCs. Such differences could be ascribed to inhomogeneous formation conditions in the classical belt that are not yet included in modeling. The variety and uncertainty of $dN/dM$ derived from state-of-the-art SI simulations currently preclude any definitive test of the SI hypothesis.

Source: arXiv (Cornell University)

DOI: 10.48550/arxiv.2609.09063

Authors: Bernstein, Gary M., Fraser, Wesley C., Eduardo, Marielle R., Grundy, William M., Hilbert, Bryan, Holman, Matthew J., Morgan, Anastasia N., Napier, Kevin J., Stansberry, John A., Trilling, David E.

Institutions: University of Pennsylvania, Herzberg Institute of Astrophysics, University of Victoria, National Research Council Canada, Space Telescope Science Institute, Center for Astrophysics Harvard & Smithsonian, Northern Arizona University, University of Michigan

Language: English

Topic: Astro and Planetary Science

Subfield: Space and Planetary Science

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, National Aeronautics and Space Administration, Space Telescope Science Institute

Awards: G103270039, G1338664626, G256731684, G433322167, G4518818167, G5568641063, G58316358, G6273510985, Collaborative Research: Jump Starting LSST Proper Motion Science with 12 Years of DECam Observations, Collaborative Research: A gravitational inventory of the solar system using high precision minor planet astrometry, G767601387, G8210229802, G8397402544

OpenAlex ID: W7212046747

Cites: 37

Cited by: 1

Related to: 10