Period variation of the classical Cepheid SV Vulpeculae over a century (1913-2022)

TL;DR

This paper presents a comprehensive analysis of over a century of observational data on the Cepheid star SV Vul, revealing its period decrease rate and emphasizing the importance of visual observations for long-term stellar monitoring.

Contribution

It provides the first detailed long-term period variation analysis of SV Vul using 338 new observations spanning over a century.

Findings

Period of SV Vul is decreasing at -250 seconds per year.

Current period of SV Vul is less than 45 days.

Visual observations are crucial for monitoring long-term period changes.

Abstract

This study analyzes 338 new times of visual, CCD, photoelectric and photographic maxima of the classical Cepheid SV Vul. The corresponding observations were made between 1913 and 2022. On this new and large observational basis, the period variations of this star of major astrophysical interest are re-visited. Without contradicting the theory or previous studies, we show that visual observations are important for a long-term monitoring of the period variations of well-selected bright Cepheids. This study establishes the period rate of change of SV Vul at -250 s/yr. Its period is currently shorter than 45 days.