Interstellar Interlopers: Number Density and Origins of 'Oumuamua-like Objects

Abstract

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 object size on detection efficiency. Using our updated detection cross-section, we infer an interstellar number density of such objects ($n_{IS}\approx 0.2{\mathrm{au}}^{-3}$). This translates to a mass density of ${\rho }_{IS}\approx 4M_{\oplus }{\mathrm{pc}}^{-3}$ which cannot be populated unless every star is contributing. We find that given current models, such a number density cannot arise from the ejection of inner solar system material during planet formation. We note that a stellar system's Oort cloud will be released after a star's main sequence life time and may provide enough material to obtain the observed density. The challenge is that Oort cloud bodies are icy and \OBJECT was observed to be dry which necessitates a crust generation mechanism.

arXiv comment5 pages, 4 figures. Accepted for publication in ApJL

References in corpus (18)

• Protoplanetary Disks and Their Evolution
• A low mass for Mars from Jupiter's early gas-driven migration
• Dynamics of Protoplanetary Disks
• Growing the gas-giant planets by the gradual accumulation of pebbles
• Capture of Trojans by Jumping Jupiter
• Oort Cloud and Scattered Disc formation during a late dynamical instability in the Solar System
• The Great Escape: How Exoplanets and Smaller Bodies Desert Dying Stars
• Steady-State Size Distributions for Collisional Populations: Analytical Solution with Size-Dependent Strength
• Interstellar Interloper 1I/2017 U1: Observations from the NOT and WIYN Telescopes
• An Observational Upper Limit on the Interstellar Number Density of Asteroids and Comets
• Spectroscopy and thermal modelling of the first interstellar object 1I/2017 U1 'Oumuamua
• The Anglo-Australian Planet Search XXIV: The Frequency of Jupiter Analogs
• Reassessing the Source of Long-Period Comets
• A Compound model for the origin of Earth's water
• Constraining the giant planets' initial configuration from their evolution: implications for the timing of the planetary instability
• Eight billion asteroids in the Oort cloud
• Pole, Pericenter, and Nodes of the Interstellar Minor Body A/2017 U1
• Constraints on planetesimal disk mass from the cratering record and equatorial ridge on Iapetus

Cited by in corpus (81)

• Initial characterization of interstellar comet 2I/Borisov
• Initial Characterization of Interstellar Comet 2I/2019 Q4 (Borisov)
• Could Solar Radiation Pressure Explain 'Oumuamua's Peculiar Acceleration?
• The Natural History of 'Oumuamua
• Spitzer Observations of Interstellar Object 1I/`Oumuamua
• The origin of interstellar asteroidal objects like 1I/2017 U1 'Oumuamua
• The Feasibility and Benefits of In Situ Exploration of `Oumuamua-like objects
• Evidence that 1I/2017 U1 (`Oumuamua) was composed of molecular hydrogen ice
• The Nucleus of Interstellar Comet 2I/Borisov
• Tidal fragmentation as the origin of 1I/2017 U1 ('Oumuamua)
• Galactic Panspermia
• Origin of 1I/'Oumuamua. I. An ejected protoplanetary disk object?
• Could 1I/'Oumuamua be an icy fractal aggregate?
• 1I/'Oumuamua as an N2 ice fragment of an exo-pluto surface. II. Generation of N2 ice fragments and the origin of 'Oumuamua
• Interstellar object 'Oumuamua as an extinct fragment of an ejected cometary planetesimal
• Galactic Tide and Local Stellar Perturbations on the Oort Cloud: Creation of Interstellar Comets
• 1I/'Oumuamua as an N2 ice fragment of an exo-Pluto surface: I. size and compositional constraints
• Subsurface Exolife
• 1I/2017 'Oumuamua-like Interstellar Asteroids as Possible Messengers from the Dead Stars
• No evidence for interstellar planetesimals trapped in the Solar System
• Oort cloud Ecology II: Extra-solar Oort clouds and the origin of asteroidal interlopers
• Constraints on the Occurrence of 'Oumuamua-Like Objects
• Origin of 1I/'Oumuamua. II. An ejected exo-Oort cloud object?
• Identifying Interstellar Objects Trapped in the Solar System through Their Orbital Parameters
• Oort cloud Ecology II: The chronology of the formation of the Oort cloud
• On the Anomalous Acceleration of 1I/2017 U1 `Oumuamua
• The interstellar object 'Oumuamua as a fractal dust aggregate
• Destruction of molecular hydrogen ice and Implications for 1I/2017 U1 (`Oumuamua)
• A hypothesis for the rapid formation of planets
• From a Different Star: 3I/ATLAS in the context of the Ōtautahi-Oxford interstellar object population model
• Implications of Captured Interstellar Objects for Panspermia and Extraterrestrial Life
• Evidence Suggesting that 'Oumuamua is the ~30 Myr-old product of a Molecular Cloud
• Capture of interstellar objects: a source of long-period comets
• Planet seeding through gas-assisted capture of interstellar objects
• Hidden Planets: Implications from 'Oumuamua and DSHARP
• Assessing the Formation of Solid Hydrogen Objects in Starless Molecular Cloud Cores
• Linking the formation and fate of exo-Kuiper belts within solar system analogues
• Interstellar Objects Outnumber Solar System Objects in the Oort Cloud
• Very Large Telescope Observations of Interstellar Comet 3I/ATLAS. II. From Quiescence to Glow: Dramatic Rise of Ni i Emission and Incipient CN Outgassing at Large Heliocentric Distances*
• Spinup and Disruption of Interstellar Asteroids by Mechanical Torques, and Implications for 1I/2017 U1 (`Oumuamua)
• On the pollution of white dwarfs by exo-Oort cloud comets
• The Galactic Interstellar Object Population: A Framework for Prediction and Inference
• Metal Pollution of Low-Mass Population III Stars through Accretion of Interstellar Objects like `Oumuamua
• The Mass Budget Necessary to Explain `Oumuamua as a Nitrogen Iceberg
• A halo of trapped interstellar matter surrounding the solar system
• Tails: Chasing Comets with the Zwicky Transient Facility and Deep Learning
• Predicting the water content of interstellar objects from galactic star formation histories
• Interstellar planetesimals: potential seeds for planet formation?
• Inferring Late Stage Enrichment of Exoplanet Atmospheres from Observed Interstellar Comets
• Effect of interstellar objects on metallicity of low-mass first stars formed in a cosmological model
• Turning up the heat on `Oumuamua
• High-Drag Interstellar Objects And Galactic Dynamical Streams
• Interstellar Asteroid Rotation with the Mechanical Torque Produced by Interstellar Medium
• Capture of interstellar objects II: by the Solar system
• Retrograde orbits excess among observable interstellar objects
• Comet C/2018 V1 (Machholz-Fujikawa-Iwamoto): dislodged from the Oort Cloud or coming from interstellar space?
• Numerical Simulations of Tidal Deformation and Resulting Light Curves of Small Bodies: Material Constraints of 99942 Apophis and 1I/`Oumuamua
• Observable Signatures of the Ejection Speed of Interstellar Objects from their Birth Systems
• Oumuamuas passing through molecular clouds
• Detecting Gravitational Scattering of Interstellar Objects Using Pulsar Timing
• Black Swans in Astronomical Data
• The New Astronomical Frontier of Interstellar Objects
• Life in Elliptical Galaxies: Hot Spheroids, Fast Stars, Deadly Comets?
• Chasing Nomadic Worlds: A New Class of Deep Space Missions
• Constraints on sub-terrestrial free-floating planets from Subaru microlensing observations
• Fitting the Light Curve of 1I/`Oumuamua with a Nonprincipal Axis Rotational Model and Outgassing Torques
• Observable tests for the light-sail scenario of interstellar objects
• Discovery of an icy and nitrogen-rich extrasolar planetesimal
• Detecting Interstellar Objects Through Stellar Occultations
• A Real-Time Search for Interstellar Impacts on the Moon
• Research Programs Arising from 'Oumuamua Considered as an Alien Craft
• The Inferred Abundance of Interstellar Objects of Technological Origin
• On The Spin Dynamics of Elongated Minor Bodies with Applications to a Possible Solar System Analogue Composition for `Oumuamua
• Exporting Terrestrial Life Out of the Solar System with Gravitational Slingshots of Earthgrazing Bodies
• Shape-Driven Selection Effects for Aspherical Near-Earth Objects in Systematic Surveys
• Implications of evaporative cooling by H${}_2$ for 1I/`Oumuamua
• The Implications of 'Oumuamua on Panspermia
• What is the amount of baryonic dark matter in galaxies?
• Machine Learning Methods for Automated Interstellar Object Classification with LSST
• Close Encounters of the Interstellar Kind: Examining the Capture of Interstellar Objects in Near Earth Orbit
• Implications for the formation of Oort cloud-like structures and interstellar comets in dense environments