The year-long flux variations in Boyajian's star are asymmetric or aperiodic

TL;DR

This study combines multi-source photometric data over a decade to analyze Boyajian's star's flux variations, revealing that the observed year-long dimming cannot be explained by short-term cyclical models, suggesting longer or evolving cycles.

Contribution

It provides a comprehensive, calibrated multi-year dataset and demonstrates that Boyajian's star's flux variations are inconsistent with short-period symmetric or asymmetric models.

Findings

Year-long flux variations of ~4% cannot be explained by cycles shorter than ten years.

If dips are transits, their period must exceed ten years or evolve significantly.

Data covers 2006-2017 from multiple sources including Kepler, Gaia, and citizen scientists.

Abstract

We combine and calibrate publicly available data for Boyajian's star including photometry from ASAS (SN, V, I), Kepler, Gaia, SuperWASP, and citizen scientist observations (AAVSO, HAO and Burke-Gaffney). Precise (mmag) photometry covers the years 2006-2017. We show that the year-long flux variations with an amplitude of ~4% can not be explained with cyclical symmetric or asymmetric models with periods shorter than ten years. If the dips are transits, their period must exceed ten years, or their structure must evolve significantly during each 4-year long cycle.