# Comet C/2018 V1 (Machholz-Fujikawa-Iwamoto): dislodged from the Oort Cloud or coming from interstellar space?

## TL;DR

This study investigates the origin of comet C/2018 V1, using dynamical simulations and Gaia data, to determine whether it originated from the Oort Cloud or interstellar space, highlighting the potential for low-velocity interstellar comets.

## Contribution

The paper applies N-body simulations and Gaia data analysis to assess the comet's origin, proposing that interstellar comets with low velocities may be more common than previously thought.

## Key findings

- C/2018 V1 may originate from the Oort Cloud or interstellar space.
- Low-velocity interstellar comets could be more frequent than assumed.
- Two solar sibling candidates suggest possible interstellar origin.

## Abstract

The chance discovery of the first interstellar minor body, 1I/2017 U1 (`Oumuamua), indicates that we may have been visited by such objects in the past and that these events may repeat in the future. Unfortunately, minor bodies following nearly parabolic or hyperbolic paths tend to receive little attention: over 3/4 of those known have data-arcs shorter than 30 d and, consistently, rather uncertain orbit determinations. This fact suggests that we may have observed interstellar interlopers in the past, but failed to recognize them as such due to insufficient data. Early identification of promising candidates by using N-body simulations may help in improving this situation, triggering follow-up observations before they leave the Solar system. Here, we use this technique to investigate the pre- and post-perihelion dynamical evolution of the slightly hyperbolic comet C/2018 V1 (Machholz-Fujikawa-Iwamoto) to understand its origin and relevance within the context of known parabolic and hyperbolic minor bodies. Based on the available data, our calculations suggest that although C/2018 V1 may be a former member of the Oort Cloud, an origin beyond the Solar system cannot be excluded. If extrasolar, it might have entered the Solar system from interstellar space at low relative velocity with respect to the Sun. The practical feasibility of this alternative scenario has been assessed within the kinematic context of the stellar neighbourhood of the Sun, using data from Gaia second data release, and two robust solar sibling candidates have been identified. Our results suggest that comets coming from interstellar space at low heliocentric velocities may not be rare.