Time-dependent spectral-feature variations of stars displaying the B[e] phenomenon III. HD 50138

• Published in: Astronomy and astrophysics (Berlin) Vol. 586; p. A116
• Main Authors: Jerabkova, T, Korcakova, D, Miroshnichenko, A, Danford, S, Zharikov, S V, Kricek, R, Zasche, P, Votruba, V, Slechta, M, Skoda, P, Janik, J
• Format: Journal Article
• Language: English
• Published: 01.02.2016
• Subjects: Astronomy; Evolutionary; Mass transfer; Mathematical models; Searching; Spectra; Stars; Time dependence
• ISSN: 0004-6361; 1432-0746
• DOI: 10.1051/0004-6361/201526290

Context. B[e] stars are anomalous objects around which extended circumstellar matter is present. The observed properties of the central star are significantly affected by the surrounding material. One of the possibilities is to analyse variations of the spectral features. For our study we choose the B[e] star HD 50138 of the FS CMa type because of the indication that this star is a post-main-sequence star, although still not highly evolved. Therefore, it can be a good object for testing evolutionary models. Our observations fill the gap in the available data. To describe the variability of HD 50138 we have monitored this star spectroscopically over the last twenty years. To search for the periodicity on short-term scales, series of night-to-night observations were also obtained. We describe the spectral variability of HD 50138 over the last twenty years. Based on these data, we determine new restrictions for future modelling. We confirm the quasi-periodic behaviour of the object's spectral variability, which probably reflects mass transfer in a binary system.