AL Pictoris and FR Piscis: two regular Blazhko RR Lyrae stars

TL;DR

This study confirms the Blazhko effect in two RR Lyrae stars through extensive multi-site observations, refining their pulsation and modulation periods, and finds no evidence of additional modulations beyond the known effects.

Contribution

The paper provides new, precise measurements of pulsation and Blazhko periods for AL Pictoris and FR Piscis, confirming the effect and demonstrating the value of coordinated amateur observations.

Findings

Confirmed Blazhko effect in both stars.

Refined pulsation periods: 0.548622 and 0.45568 days.

Refined Blazhko periods: 34.07 and 51.31 days.

Abstract

The results presented are a continuation of observing campaigns conducted by a small group of amateur astronomers interested in the Blazhko effect of RR Lyrae stars. The goal of these observations is to confirm the RR Lyrae Blazhko effect and to detect any additional Blazhko modulation which cannot be identified from all sky survey data-mining. The Blazhko effect of the two observed stars is confirmed, but no additional Blazhko modulations have been detected. The observation of the RR Lyrae star AL Pic during 169 nights was conducted from San Pedro de Atacama (Chile). From the observed light curve, 49 pulsation maxima have been measured. Fourier analyses of (O-C), magnitude at maximum light (Mmax) and the complete light curve have provided a confirmation of published pulsation and Blazhko periods, 0.548622 and 34.07 days, respectively. The second multi-longitude observation campaign focused on the RR Lyrae star FR Psc was performed from Europe, United States and Chile. Fourier analyses of the light curve and of 59 measured brightness maxima have improved the accuracy of pulsation and Blazhko periods which are 0.45568 and 51.31 days, respectively. For both stars, no additional Blazhko modulations have been detected.