Photometric study of the star with changing Blazhko effect: TV~Bootis

TL;DR

This paper presents a detailed photometric analysis of the rare Blazhko effect in the RRc star TV Boo, revealing a very short primary modulation period and complex multi-periodic behavior, contributing new insights into stellar pulsation phenomena.

Contribution

It provides the first detailed photometric study of TV Boo's Blazhko effect, identifying its short modulation period and physical parameters, expanding understanding of RRc star variability.

Findings

Primary Blazhko period of 9.7374 days, one of the shortest among RRc stars.

Detection of a secondary modulation period of 21.5 days.

Indications of long-term changes affecting TV Boo's light curve.

Abstract

This study investigates periodic modulation of the light curve of the RRc star TV Boo and its physical parameters based on photometric data. This phenomenon, known as Blazhko effect, is quite rare among RRc stars. Frequency analysis based on the data gathered at Masaryk University Observatory (MUO) and also using SuperWASP data revealed symmetrically structured peaks around the main pulsation frequency and its harmonics, which indicate two modulation components of the Blazhko period. The main modulation periodicity was found to be 9.7374(54) d. This is one of the shortest known Blazhko periods among RRc stars. The second modulation period 21.5(2) d causes changes of the Blazhko effect itself. Some indices show that TV Boo could be affected by long-term changes in the order of years. Basic physical parameters were estimated via a MUO V light curve solution using Fourier parameters. TV Boo seems to be a low-metalicity star with [Fe/H]=-1.89.