Gálvez, M. C.Montes Gutiérrez, DavidFernández Figueroa, María JoséCastro Rubio, Elisa DeCornide Castro-Piñeiro, Manuel2023-06-202023-06-202009-040004-625610.1088/0004-6256/137/4/3965https://hdl.handle.net/20.500.14352/44639© 2009. The American Astronomical Society. All rights reserved. This work was supported by the Spanish "Programa Nacional de Astronomía y Astrofísica" under grants AYA2005-02750 and AYA2008-00695, and the "Comunidad de Madrid" under PRICIT project S-0505/ESP-0237 (ASTROCAM).This paper describes a multiwavelength optical study of chromospheres in two X-ray/EUV-selected active binary stars with strong H alpha emission, V789 Mon (2RE J0725-002) and GZ Leo (2RE J1101+223). The goal of the study is to determine radial velocities and fundamental stellar parameters in chromospherically active binary systems in order to include them in the activity-rotation and activity-age relations. We carried out high-resolution echelle spectroscopic observations and applied spectral-subtraction technique in order to measure emission excesses due to chromosphere. The detailed study of activity indicators allowed us to characterize the presence of different chromospheric features in these systems and enabled to include them in a larger activity-rotation survey. We computed radial velocities of the systems using cross-correlation with the radial velocity standards. The double-line spectral binarity was confirmed and the orbital solutions improved for both systems. In addition, other stellar parameters such as spectral types, projected rotational velocities (v sin i) and the equivalent width of the lithium Li i λ6707.8 Å absorption line were determined.engjournal articlehttp://dx.doi.org/10.1088/0004-6256/137/4/3965http://iopscience.iop.org/open access52RS canum-venaticorumDisk populationRadial-velocityUrsae majorisH-alphaX-rayStarsYoungSingleVariabilityAstrofísicaAstronomía (Física)