WISE Brown Dwarf Binaries: The Discovery of a T5+T5 and a T8.5+T9 System

TL;DR

This paper reports the discovery of two brown dwarf binary systems using high-resolution imaging, providing valuable data for understanding brown dwarf formation, evolution, and atmospheric properties.

Contribution

First high-resolution imaging results of brown dwarf binaries from WISE data, including a T5+T5 and a T8.5+T9 system, advancing knowledge of substellar multiplicity.

Findings

Discovered a T5+T5 binary with nearly equal masses.

Identified a faint companion to a T8.5 dwarf, estimated as T9.

Demonstrated the effectiveness of WISE data and adaptive optics in finding brown dwarf binaries.

Abstract

The multiplicity properties of brown dwarfs are critical empirical constraints for formation theories, while multiples themselves provide unique opportunities to test evolutionary and atmospheric models and examine empirical trends. Studies using high-resolution imaging can not only uncover faint companions, but they can also be used to determine dynamical masses through long-term monitoring of binary systems. We have begun a search for the coolest brown dwarfs using preliminary processing of data from the Wide-field Infrared Survey Explorer (WISE) and have confirmed many of the candidates as late-type T dwarfs. In order to search for companions to these objects, we are conducting observations using the Laser Guide Star Adaptive Optics system on Keck II. Here we present the first results of that search, including a T5 binary with nearly equal mass components and a faint companion to a T8.5 dwarf with an estimated spectral type of T9.