# The Interstellar Object ’Oumuamua as a Fractal Dust Aggregate

@article{Flekky2019TheIO,
title={The Interstellar Object ’Oumuamua as a Fractal Dust Aggregate},
author={Eirik G Flekk{\o}y and Jane X. Luu and Renaud Toussaint},
journal={The Astrophysical Journal},
year={2019}
}
• Published 16 October 2019
• Physics
• The Astrophysical Journal
The first known interstellar object 'Oumuamua exhibited a nongravitational acceleration that appeared inconsistent with cometary outgassing, leaving radiation pressure as the most likely force. Bar the alien lightsail hypothesis, an ultra-low density due to a fractal structure might also explain the acceleration of 'Oumuamua by radiation pressure (Moro-Martin 2019). In this paper we report a decrease in 'Oumuamua's rotation period based on ground-based observations, and show that this spin-down…
12 Citations

## Figures and Tables from this paper

’Oumuamua as a Cometary Fractal Aggregate: The “Dust Bunny” Model
• Physics
• 2020
The first known interstellar object, 1I/2017 U1 'Oumuamua, displayed such unusual properties that its origin remains a subject of much debate. We propose that 'Oumuamua's properties could be
The Nucleus of Interstellar Comet 2I/Borisov
• Physics
• 2019
We present high resolution imaging observations of interstellar comet 2I/Borisov (formerly C/2019 Q4) obtained using the Hubble Space Telescope. Scattering from the comet is dominated by a coma of
1I/‘Oumuamua as an N 2 Ice Fragment of an exo‐Pluto Surface: I. Size and Compositional Constraints
• Physics
Journal of Geophysical Research: Planets
• 2021
The origin of the interstellar object 1I/'Oumuamua has defied explanation. We perform calculations of the non-gravitational acceleration that would be experienced by bodies composed of a range of
Constraints on the Occurrence of ‘Oumuamua-Like Objects
• Physics
The Astrophysical Journal
• 2021
At present, there exists no consensus in the astronomical community regarding either the bulk composition or the formation mechanism for the interstellar object 1I/2017 U1 (‘Oumuamua). With the goal
The New Astronomical Frontier of Interstellar Objects
• Physics
• 2021
The upcoming commencement of the Vera C. Rubin Observatory’s Legacy Survey of Space of Time (LSST) will greatly enhance the discovery rate of interstellar objects (ISOs). ‘Oumuamua and Borisov were
Evolution of porous dust grains in protoplanetary discs – I. Growing grains
• Physics
• 2020
One of the main problems in planet formation, hampering the growth of small dust to planetesimals, is the so-called radial-drift barrier. Pebbles of cm to dm sizes are thought to drift radially
Could 1I/2017 U1 ‘Oumuamua be a Solar Sail Hybrid?
• 2020
Motivated by shortcomings of natural explanations for the first interstellar object, 'Oumuamua, this study considers implications of an artificial origin hypothesis inspired and constrained by
Project Lyra: Catching 1I/'Oumuamua -- Using Laser Sailcraft in 2030
• Physics
• 2020
Discovered in October 2017, the interstellar object designated 1I/'Oumuamua was the first such object to be observed travelling through our solar system. 1I/'Oumuamua has other characteristics never
Anomalous Sun Flyby of 1I/2017 U1 (Oumuamua)
• Physics
• 2020
The findings of Micheli et al. (Nature2018, 559, 223–226) that 1I/2017 U1 (Oumuamua) showed anomalous orbital accelerations have motivated us to apply an impact model of gravity in search for an
Constraining the orientation of the spin axes of extrasolar minor bodies 1I/2017 U1 (‘Oumuamua) and 2I/Borisov
• Physics
• 2020
Context. The orientation of the spin axis of a comet is defined by the values of its equatorial obliquity and its cometocentric longitude of the Sun. These parameters can be computed from the

## References

SHOWING 1-10 OF 42 REFERENCES
Could 1I/’Oumuamua be an Icy Fractal Aggregate?
1I/'Oumuamua was the first interstellar interloper that has been detected and it showed a non-gravitational acceleration (Micheli et al. 2018) that cannot be accounted for by outgassing, given the
Fractal signatures in analogs of interplanetary dust particles
• Physics
• 2014
Abstract Interplanetary dust particles (IDPs) are an important constituent of the earth׳s stratosphere, interstellar and interplanetary medium, cometary comae and tails, etc. Their physical and
Interstellar Interlopers: Number Density and Origin of ‘Oumuamua-like Objects
• Physics
• 2018
We provide a calculation of Pan-STARRS' ability to detect objects similar to the interstellar object 1I/2017 U1 (hereafter 'Oumuamua), including the most detectable approach vectors and the effect of
Origin of 1I/’Oumuamua. II. An Ejected Exo-Oort Cloud Object?
1I/'Oumuamua is the first detected interstellar interloper. We test the hypothesis that it is representative of a background population of exo-Oort cloud objects ejected under the effect of post-main
Spin Evolution and Cometary Interpretation of the Interstellar Minor Object 1I/2017 ’Oumuamua
Observations of the first interstellar minor object 1I/2017 'Oumuamua did not reveal direct signs of outgassing that would have been natural if it had volatile-rich composition. However, a recent
Origin of 1I/’Oumuamua. I. An Ejected Protoplanetary Disk Object?
1I/'Oumuamua is the first interstellar interloper to have been detected. Because planetesimal formation and ejection of predominantly icy objects are common by-products of the star and planet
Tumbling motion of 1I/‘Oumuamua and its implications for the body’s distant past
• Physics
• 2018
Models of the Solar System’s evolution show that almost all the primitive material leftover from the formation of the planets was ejected to the interstellar space as a result of dynamical
Spitzer Observations of Interstellar Object 1I/‘Oumuamua
1I/'Oumuamua is the first confirmed interstellar body in our solar system. Here we report on observations of 'Oumuamua made with the Spitzer Space Telescope on 2017 November 21–22 (UT). We integrated
Col-OSSOS: Colors of the Interstellar Planetesimal 1I/‘Oumuamua
The recent discovery by Pan-STARRS1 of 1I/2017 U1 (`Oumuamua), on an unbound and hyperbolic orbit, offers a rare opportunity to explore the planetary formation processes of other stars, and the
Interstellar Interloper 1I/2017 U1: Observations from the NOT and WIYN Telescopes
We present observations of the interstellar interloper 1I/2017 U1 ('Oumuamua) taken during its 2017 October flyby of Earth. The optical colors B-V = 0.70$\pm$0.06, V-R = 0.45$\pm$0.05, overlap those