Significant interstellar object production by close stellar flybys

  title={Significant interstellar object production by close stellar flybys},
  author={Susanne Pfalzner and Luis A. Vargas and Asmita Bhandare and Dimitri Veras},
  journal={Astronomy \& Astrophysics},
Context. Within just two years, two interstellar objects (ISOs) – 1I/‘Oumuamua and 2I/Borisov – have been discovered, the first of their kind. Large quantities of planetesimals form as a by-product of planet formation. Therefore, it seems likely that ISOs are former planetesimals that became somehow unbound from their parent star. The discoveries raise the question of the dominant ISO formation process. Aims. Here, we concentrate on planetesimals released during another star’s close flybys… 

The New Astronomical Frontier of Interstellar Objects

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

Predicting the Water Content of Interstellar Objects from Galactic Star Formation Histories

Planetesimals inevitably bear the signatures of their natal environment, preserving in their composition a record of the metallicity of their system’s original gas and dust, albeit one altered by the

Oort cloud Ecology

Jan Hendrik Oort hypothesized the existence of a distant cloud of cometary objects that orbit the Sun based on a spike in the reciprocal orbital separation at 1∕a  ≲  10−4 au−1. The Oort cloud is the



A Hypothesis for the Rapid Formation of Planets

The discovery of 1I/‘Oumuamua confirmed that planetesimals must exist in great numbers in interstellar space. Originally generated during planet formation, they are scattered from their original

A search for the origin of the interstellar comet 2I/Borisov

The discovery of the second interstellar object 2I/Borisov on 2019 August 30 raises the question of whether it was ejected recently from a nearby stellar system. Here we compute the asymptotic

A brief visit from a red and extremely elongated interstellar asteroid

Observations and analysis of the object 1I/2017 U1 (‘Oumuamua) that demonstrate its extrasolar trajectory, and that enable comparisons to be made between material from another planetary system and from the authors' own, reveal it to be asteroidal with no hint of cometary activity despite an approach within 0.25 astronomical units of the Sun.

Circumstellar disks do erase the effects of stellar flybys on planetary systems

Context. Most stars form in embedded clusters. Stellar flybys may affect the orbital architecture of the systems by exciting the eccentricity and causing dynamical instability. Aims. Since,

Effects of inclined star-disk encounter on protoplanetary disk size

Most, if not all, young stars are initially surrounded by protoplanetary disks. Owing to the preferential formation of stars in stellar clusters, the protoplanetary disks around these stars may

1I/‘Oumuamua as a Tidal Disruption Fragment from a Binary Star System

1I/‘Oumuamua is the first known interstellar small body, probably being only about 100 m in size. Against expectations based on comets, ‘Oumuamua does not show any activity and has a very elongated

The Dynamics of Interstellar Asteroids and Comets within the Galaxy: An Assessment of Local Candidate Source Regions for 1I/’Oumuamua and 2I/Borisov

The low velocity of interstellar asteroid 1I/’Oumuamua with respect to our galaxy’s local standard of rest implies that it is young. Adopting the young age hypothesis, we assess possible origin


We study the evolution of planetesimals in evolved gaseous disks that orbit a solar-mass star and harbor a Jupiter-mass planet at a p ≈ 5 ?> AU. The gas dynamics are modeled with a three-dimensional

Evidence for Early Stellar Encounters in the Orbital Distribution of Edgeworth-Kuiper Belt Objects

We show that early stellar encounters can explain the high eccentricities and inclinations observed in the outer part (>42 AU) of the Edgeworth-Kuiper Belt (EKB). We consider the proto-Sun as a

Cradle(s) of the Sun

The Sun likely formed as part of a group of stars. A close stellar flyby by one of the solar siblings is probably responsible for the sharp outer edge in the solar system's mass distribution. The