ON QUASI-PERIODIC BRIGHTNESS VARIATIONS OF P Cygni: Dedicated to the 110th anniversary of the academician E. Kharadze

• Published in: Astrophysics 2018-03, Vol.61 (1), p.22
• Main Authors: Kochiashvili, N, Beradze, S, Natsvlishvili, R, Kochiashvili, I, Vardosanidze, M, Pannicke, A
• Format: Article
• Language: English
• Subjects: Brightness (Photometry); Observations; Optical properties; Stars
• ISSN: 0571-7256; 1573-8191
• DOI: 10.1007/s10511-018-9512-2

Until recent decades, it was considered that all Luminous Blue Variables are single massive and high luminosity stars. Now for several of them a companion has been found. The opinion exists that P Cygni also has a companion with an orbital period of about seven years. In accordance with this hypothesis, a known powerful eruption occurred near the periastron point. P Cygni, as well as several other wellknown Luminous Blue Variable (LBV) stars, is a so-called "Supernova Impostor" because it survived after a powerful outburst. However, there were cases during the last decade when a LBV star survived after a powerful giant eruption, and then after a few years, explode as a supernova. Because the real reason for the great eruption and characteristic light variability of LBV, including P Cygni, is not established yet, any kind of photometric and spectral observational data is very significant. We present the results of analysis of the long-term photometric observations of hypergiant P Cygni. On the basis of these data, different quasi-periodic brightness changes of the star were revealed.