# OGLE-2018-BLG-0022: A Nearby M-dwarf Binary

## TL;DR

This paper presents the discovery and analysis of a nearby low-mass binary star system through microlensing observations, providing precise mass and distance measurements that enhance understanding of M-dwarf binaries.

## Contribution

The study reports the first detailed characterization of a nearby M-dwarf binary via microlensing, including precise mass and distance estimates, demonstrating microlensing's potential for studying low-mass stars.

## Key findings

- The binary consists of M3 and M7 type stars with masses 0.375 and 0.098 solar masses.
- The system is located at approximately 1 kpc from Earth, closer than most microlensing events.
- Future AO observations could confirm the lens masses independently.

## Abstract

We report observations of the binary microlensing event OGLE-2018-BLG-0022, provided by the ROME/REA Survey, which indicate that the lens is a low-mass binary star consisting of M3 (0.375+/-0.020 Msun) and M7 (0.098+/-0.005 Msun) components. The lens is unusually close, at 0.998+/-0.047 kpc, compared with the majority of microlensing events, and despite its intrinsically low luminosity, it is likely that AO observations in the near future will be able to provide an independent confirmation of the lens masses.