An Investigation of New Brown Dwarf Spectral Binary Candidates From the Backyard Worlds: Planet 9 Citizen Science Initiative

TL;DR

This study identifies three new brown dwarf spectral binary candidates discovered via citizen science, with follow-up spectroscopy suggesting potential binarity or variability, highlighting their importance for future detailed investigations.

Contribution

The paper reports the discovery and initial characterization of three brown dwarf candidates, utilizing citizen science and spectral analysis to identify potential binaries or variable objects.

Findings

Binary templates fit better than single standards

Two candidates likely binaries with specific spectral types

One candidate shows signs of strong variability

Abstract

We present three new brown dwarf spectral binary candidates: CWISE J072708.09$-$360729.2, CWISE J103604.84$-$514424.4, and CWISE J134446.62$-$732053.9, discovered by citizen scientists through the Backyard Worlds: Planet 9 project. Follow-up near-infrared spectroscopy shows that each of these objects is poorly fit by a single near-infrared standard. We constructed binary templates and found significantly better fits, with component types of L7+T4 for CWISE J072708.09$-$360729.2, L7+T4 for CWISE J103604.84$-$514424.4, and L7+T7 for CWISE J134446.62$-$732053.9. However, further investigation of available spectroscopic indices for evidence of binarity and large amplitude variability suggests that CWISE J072708.09$-$360729.2 may instead be a strong variability candidate. Our analysis offers tentative evidence and characterization of these peculiar brown dwarf sources, emphasizing their value as promising targets for future high-resolution imaging or photometric variability studies.