A photometric study of the southern Blazhko star SS For Unambiguous detection of quintuplet components

TL;DR

This study analyzes photometric data of the Blazhko star SS For, revealing high-order triplet and quintuplet frequency components, and examines the light curve variations and metallicity, contributing to understanding its pulsation behavior.

Contribution

The paper provides the first unambiguous detection of quintuplet components in SS For and compares photometric and spectroscopic metallicity measurements.

Findings

Detection of high-order triplet and quintuplet frequency components.

Light curve shape varies significantly over the Blazhko cycle.

Spectroscopic and photometric metallicity estimates are in good agreement.

Abstract

We present our analysis of photometric data in the Johnson B and V filter of the southern Blazhko star SS For. In parallel, we analyzed the V observations obtained with the ASAS-3 photometry of the star gathered between 2000 and 2008. In the frequency spectra resulting from a Fourier analysis of our data, the triplet structure is detectable up to high order, both in the B and V data. Moreover, we find evidence for quintuplet components. We confirm from our data that the modulation components decrease less steeply than the harmonics of the main frequency. We derived the variations of the Fourier parameters quantifying the light curve shape over the Blazhko cycle. There is good agreement between the spectroscopic abundance and the metallicity determined from the Fourier parameters of the average light curve. SS For is peculiar as a Blazhko star because of its strong variations around minimum light.