English

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

Solar and Stellar Astrophysics 2023-04-19 v1 Earth and Planetary Astrophysics Astrophysics of Galaxies

Abstract

Disintegrating multiple systems have been previously discovered from kinematic studies of the Hipparcos\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 Gaia\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.

Keywords

Cite

@article{arxiv.2304.02236,
  title  = {Identifying and characterizing ultracool dwarfs ejected from post-encounter disintegrating systems},
  author = {Alexandra K. P. Yip and Radostin Kurtev and David J. Pinfield and Federico Marocco and Mariusz Gromadzki and Julio A. Carballo-Bello},
  journal= {arXiv preprint arXiv:2304.02236},
  year   = {2023}
}

Comments

Accepted for publication in MNRAS. 17 pages, 8 figures, 4 tables

R2 v1 2026-06-28T09:50:15.716Z