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

Abstract

ABSTRACT1I/'Oumuamua is the first known interstellar small body (Bacci et al. 2017), probably being only about 100 m in size. Against expectations based on comets, 'Oumuamua does not show any activity and has a very elongated figure (Meech et al. 2017), and also exhibits undamped rotational tumbling . In contrast, 'Oumuamua's trajectory indicates that it was moving with the local stars, as expected from a low-velocity ejection from a relatively nearby system (Mamajek 2017). Here I assume that 'Oumuamua is typical of 100-m interstellar objects, and speculate on its origins. I find that giant planets are relatively inefficient at ejecting small bodies from inner solar systems of main-sequence stars, and that binary systems offer a much better opportunity for ejections of non-volatile bodies. I also conclude that 'Oumuamua is not a member of a collisional population, which could explain its dramatic difference from small asteroids. I observe that 100-m small bodies are expected to carry little mass in realistic collisional populations, and that occasional events when whole planets are disrupted in catastrophic encounters may dominate interstellar population of 100-m fragments. Unlike the Sun or Jupiter, red dwarf stars are very dense and are capable of thoroughly tidally disrupting terrestrial planets. I conclude that the origin of 'Oumuamua as a fragment from a planet that was tidally disrupted and then ejected by a dense member of a binary system could explain its peculiarities.

Project Lyra: Catching 1I/‘Oumuamua – Mission opportunities after 2024

“…Since its discovery in October 2017, 1I/'Oumuamua has generated considerable interest from both academia and the media. The academic debate is still ongoing and topics are as wide-ranging as the object's shape [4][5][6][7][8][9], its composition [4,5,[10][11][12][13][14], its origin [15][16][17][18][19][20][21], explanation for an observed acceleration [22,23], and estimates for the population of similar objects [2,5]. Given that 1I/'Oumuamua is the first confirmed interstellar object that has been discovered intercepting our Solar System, it might turn out to be the only opportunity to study interstellar material in-situ for decades or even centuries to come [2,5].…”

Radio SETI observations of the interstellar object ′OUMUAMUA

“…Such a cigar-shaped morphology has never been found for a solar system asteroid. Several suggestions have been made as to how a natural object can be this elongated (e.g., [5]).…”

1I/‘Oumuamua as an N2 Ice Fragment of an Exo‐Pluto Surface II: Generation of N2 Ice Fragments and the Origin of ‘Oumuamua

“…However, even if fragments could only be ejected from stars of spectral type G and later, this would only cut down the frequency of collisional fragments by a factor of 2. It is worth noting that a number of physical processes have been identified that could lead to fragments being ejected from a young stellar system (Ćuk, 2018; Raymond, Armitage, Veras, Quintana, 2018; Raymond, Armitage, & Veras, 2018; Wyatt et al., 2017; 'Oumuamua ISSI Team et al., 2019), including gravitational interactions with stars in a stellar birth cluster, or interaction with a binary star (Holman & Wiegert, 1999). These factors would increase the rate of ejection.…”