The interesting binary system GJ375

DÍAZ, R.; GONZALEZ, J. F.; CINCUNEGUI, C.; MAUAS, P. J. D.

Capilla del Monte, Córdoba, Argentina

Congreso; 49 Reunión Anual de la Asociación Argentina de Astronomia; 2006

Asociación Argentina de Astronomía

We study the spectroscopic binary system GJ 375 using medium resolution echelle spectra obtained at the Jorge Sahade telescope at CASLEO. Using the method described by Gonzalez & Levato (2006) we separate the composite spectra and confirm the spectral types of both components are similar (dMe3.5). Precise masurements of the orbital period (P = 1.87844 days) and minimum masses (M1 sin3 i = 0.33 Msun and M2 sin3 i = 0.35 Msun) are obtained. Using photometric data from the ASAS database (Pojmanski 2002) we find variations of around 0.04 mag, the amplitude of which changes periodically with time, showing a period of around 700 days. We interpret this as a signs of cyclic stellar activity in the system, with both components in phase.