Photometric and H$α$ observations of LSI+61303: detection of a $\sim$26 day V and JHK band modulation

J. M. Paredes; P. Marziani; J. Marti; J. Fabregat; M. J. Coe; C. Everall; F. Figueras; C. Jordi; A. J. Norton; T. Prince; V. Reglero; P. Roche; J. Torra; S. J. Unger; R. Zamanov

arXiv · astro-ph/9402016

Photometric and H$α$ observations of LSI+61303: detection of a $\sim$26 day V and JHK band modulation

J. M. Paredes·P. Marziani·J. Marti·J. Fabregat·M. J. Coe·C. Everall·F. Figueras·C. Jordi·A. J. Norton·T. Prince·V. Reglero·P. Roche·J. Torra·S. J. Unger·R. Zamanov

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Abstract

We present new optical and infrared photometric observations and high resolution H$α$ spectra of the periodic radio star \lsi. The optical photometric data set covers the time interval 1985-1993 and amounts to about a hundred nights. A period of $\sim$26 days is found in the V band. The infrared data also present evidence for a similar periodicity, but with higher amplitude of variation (0\rmag 2). The spectroscopic observations include 16 intermediate and high dispersion spectra of \lsi\ collected between January 1989 and February 1993. The H$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\ 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.

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J. M. Paredes, P. Marziani, J. Marti, J. Fabregat, M. J. Coe, C. Everall, F. Figueras, C. Jordi, A. J. Norton, T. Prince, V. Reglero, P. Roche, J. Torra, S. J. Unger, R. Zamanov. 1994-02-07. Photometric and H$α$ observations of LSI+61303: detection of a $\sim$26 day V and JHK band modulation. https://arxiv.org/abs/astro-ph/9402016

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