Constraints on the Density and Internal Strength of 1I/'Oumuamua

Abstract

1I/'Oumuamua was discovered by the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS 1) on 19 October 2017. Unlike all previously discovered minor planets this object was determined to have eccentricity $e>1.0$, suggesting an interstellar origin. Since this discovery and within the limited window of opportunity, several photometric and spectroscopic studies of the object have been made. Using the measured light curve amplitudes and rotation periods we find that, under the assumption of a triaxial ellipsoid, a density range $1500<\rho <2800$ kg m${}^{-3}$ matches the observations and no significant cohesive strength is required. We also determine that an aspect ratio of $6\pm 1:1$ is most likely after accounting for phase-angle effects and considering the potential effect of surface properties. This elongation is still remarkable but less than some other estimates.

8 pages; accepted for publication in ApJL

References in corpus (6)

• Col-OSSOS: Colors of the Interstellar Planetesimal 1I/`Oumuamua
• APO Time Resolved Color Photometry of Highly-Elongated Interstellar Object 1I/'Oumuamua
• The tumbling rotational state of 1I/`Oumuamua
• On the rotation period and shape of the hyperbolic asteroid 1I/`Oumuamua (2017) U1 from its lightcurve
• Implications for planetary system formation from interstellar object 1I/2017 U1 (`Oumuamua)
• 2004 TT357: A potential contact binary in the Trans-Neptunian belt

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• Spin Evolution and Cometary Interpretation of the Interstellar Minor Object 1I/2017 'Oumuamua
• On the Anomalous Acceleration of 1I/2017 U1 `Oumuamua
• Possible Interstellar meteoroids detected by the Canadian Meteor Orbit Radar
• Evidence Suggesting that 'Oumuamua is the ~30 Myr-old product of a Molecular Cloud
• Asteroid Photometry from the Transiting Exoplanet Survey Satellite: A Pilot Study
• The Solar System Notification Alert Processing System (SNAPS): Design, Architecture, and First Data Release (SNAPShot1)
• On the aspect ratio of Oumuamua: less elongated shape for irregular surface properties
• Removing Aliases in Time-Series Photometry
• The DECam Ecliptic Exploration Project (DEEP). VII. The Strengths of Three Superfast Rotating Main-belt Asteroids from a Preliminary Search of DEEP Data
• Infrared Lightcurves of Near Earth Objects
• Configuration of Single Giant Planet Systems Generating `Oumuamua-Like Interstellar Asteroids
• Gyr-timescale destruction of high-eccentricity asteroids by spin and why 2006 HY51 has been spared
• The Implications of 'Oumuamua on Panspermia