Identification of strong photometric activity in the components of LHS 1070

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, ΔB > 8.2 mag, ever observed in a flare star.

5 pages, 5 figures, accepted for publication in A&A

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Cited by in corpus (3)

• Hα Emission Variability in Active M Dwarfs
• Orbits and Masses in the multiple system LHS 1070
• Exploring the short-term variability of H$\alpha$ and H$\beta$ emissions in a sample of M dwarfs