Paredes i Poy, Josep MariaMarziani, P.Martí Ribas, JosepFabregat, JaimeCoe, M. J.Everall, C.Figueras Siñol, FrancescaJordi i Nebot, CarmeNorton, A. J.Prince, T.Reglero, V.Roche, P.Torra Roca, JorgeUnger, S. J.Zamanov, R. K.2013-08-282013-08-2819940004-6361https://hdl.handle.net/2445/45406We present new optical and infrared photometric observations and high resolution H α spectra of the periodic radio star LSI+61◦303. The optical photometric data set covers the time interval 1985-1993 and amounts to about a hundred nights. A period of ∼26 days is found in the V band. The infrared data also present evidence for a similar periodicity, but with higher amplitude of variation ((0.m 2). The spectroscopic observations include 16 intermediate and high dispersion spectra of LSI+61◦303 collected between January 1989 and February 1993. The H α emission line profile and its variations are analyzed. Several emission line parameters -- among them the H α EW and the width of the H α red hump -- change strongly at or close to radio maximum, and may exhibit periodic variability. We also observe a significant change in the peak separation. The H α profile of LSI+61◦303 does not seem peculiar for a Be star. However, several of the observed variations of the H α profile can probably be associated with the presence of the compact, secondary star.9 p.application/pdfeng(c) Springer Verlag, 1994EstelsEstels binaris de raigs XAstronomia de raigs XAstrofísicaStarsX-ray binariesX-ray astronomyAstrophysicsinfo:eu-repo/semantics/article0877932013-08-28info:eu-repo/semantics/openAccess