Identification of strong photometric activity in the components of LHS 1070

TL;DR

This study reports strong flaring activity in two components of the low-mass triple system LHS 1070, providing insights into stellar activity and magnetic fields in such stars.

Contribution

It identifies the flaring components in LHS 1070 and measures their magnetic field strength and flare energy, improving astrometric data for the system.

Findings

Components A and B exhibit strong photometric flares.

The flare in component B has an energy of ~2.0 x 10^{33} ergs.

The observed flare amplitude exceeds 8.2 magnitudes.

Abstract

Activity in low-mass stars is an important ingredient in the evolution of such objects. Fundamental physical properties such as age, rotation, magnetic field are correlated with activity. Aims: We show that two components of the low-mass triple system LHS 1070 exhibit strong flaring activity. We identify the flaring components and obtained an improved astrometric solution for the LHS 1070 A/(B+C) system. Methods: Time-series CCD observations were used to monitor LHS 1070 in the B and I_C bands. H-band data were used to obtain accurate astrometry for the LHS 1070 A/(B+C) system. Results: We have found that two components of the triple system LHS 1070 exhibit photometric activity. We identified that components A and B are the flaring objects. We estimate the total energy, ~2.0 x 10^{33} ergs, and the magnetic field strength, ~5.5 kG, of the flare observed in LHS 1070 B. This event is the largest amplitude, \Delta B > 8.2 mag, ever observed in a flare star.