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arXiv · 2304.02236

Identifying and characterizing ultracool dwarfs ejected from post-encounter disintegrating systems

Alexandra K. P. Yip·Radostin Kurtev·David J. Pinfield·Federico Marocco·Mariusz Gromadzki·Julio A. Carballo-Bello
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Abstract

Disintegrating multiple systems have been previously discovered from kinematic studies of the $\it Hipparcos$ catalogue. They are presumably the result of dynamical encounters taking place in the Galactic disk between single/multiple systems. In this paper, we aim to expand the search for such systems, to study their properties, as well as to characterize possible low-mass ejecta (i.e. brown dwarfs and planets). We have assembled a list of 15 candidate systems using astrometry from the Tycho-Gaia astrometric solution (later upgraded with $\it Gaia$ DR3), and here we present the discovery and follow-up of 5 of them. We have obtained DECam imaging for all 5 systems and by combining near-infrared photometry and proper motion, we searched for ultra-cool ejected components. We find that the system consisting of TYC 7731-1951-1, TYC 7731-2128 AB, and TYC 7731-1995-1ABC?, contains one very promising ultra-cool dwarf candidate. Using additional data from the literature, we have found that 3 out of 5 disintegrating system candidates are likely to be true disintegrating systems.

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Alexandra K. P. Yip, Radostin Kurtev, David J. Pinfield, Federico Marocco, Mariusz Gromadzki, Julio A. Carballo-Bello. 2023-04-05. Identifying and characterizing ultracool dwarfs ejected from post-encounter disintegrating systems. https://doi.org/10.1093/mnras%2Fstad1037

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