Discovery of 34 low-mass comoving systems using NOIRLab Source Catalog DR2

TL;DR

This paper reports the discovery of 34 low-mass comoving systems with ultra-cool dwarfs using the NOIRLab Source Catalog DR2, enhancing understanding of low-mass system formation and evolution.

Contribution

It introduces a new method of identifying low-mass comoving systems using high-resolution proper motion data from NSC DR2, leading to 34 new system discoveries.

Findings

34 new low-mass comoving systems identified

Systems include ultra-cool dwarfs with primaries in K and M spectral types

Physical separations range from 169 to 8487 AU

Abstract

We present the discovery of 34 comoving systems containing an ultra-cool dwarf found by means of the NOIRLab Source Catalog (NSC) DR2. NSC's angular resolution of $\sim$1" allows for the detection of small separation binaries with significant proper motions. We used the catalog's accurate proper motion measurements to identify the companions by cross-matching a previously compiled list of brown dwarf candidates with NSC DR2. The comoving pairs consist of either a very low-mass star and an ultra-cool companion, or a white dwarf and an ultra-cool companion. The estimated spectral types of the primaries are in the K and M dwarf regimes, those of the secondaries in the M, L and T dwarf regimes. We calculated angular separations between $\sim$2 and $\sim$56", parallactic distances between $\sim$43 and $\sim$261 pc and projected physical separations between $\sim$169 and $\sim$8487 AU. The lowest measured total proper motion is 97 mas yr$^{-1}$, the highest 314 mas yr$^{-1}$. Tangential velocities range from $\sim$23 to $\sim$187 km s$^{-1}$. We also determined comoving probabilities, estimated mass ratios and calculated binding energies for each system. We found no indication of possible binarity for any component of the 34 systems in the published literature. The discovered systems can contribute to the further study of the formation and evolution of low-mass systems as well as to the characterization of cool substellar objects.