A Systematic Search for Main-Sequence Dipper Stars Using the Zwicky Transient Facility

TL;DR

This study systematically searches for main-sequence dipper stars using Gaia and ZTF data, discovering 81 new candidates with diverse light curve behaviors, and explores potential mechanisms behind their dimming events.

Contribution

It introduces a novel light curve scoring algorithm and a scalable workflow to identify dipper stars across millions of light curves, expanding the known sample significantly.

Findings

Identified 81 new dipper star candidates.

Diverse light curve dimming shapes observed, with timescales from days to years.

No clear periodicity or infrared excess detected in many candidates.

Abstract

Main-sequence dipper stars, characterized by irregular and often aperiodic luminosity dimming events, offer a unique opportunity to explore the variability of circumstellar material and its potential links to planet formation, debris disks, and broadly star-planet interactions. The advent of all-sky time-domain surveys has enabled the rapid discovery of these unique systems. We present the results of a large systematic search for main-sequence dipper stars, conducted across a sample of 63 million FGK main-sequence stars using data from Gaia eDR3 and the Zwicky Transient Facility (ZTF) survey. Using a novel light curve scoring algorithm and a scalable workflow tailored for analyzing millions of light curves, we have identified 81 new dipper star candidates. Our sample reveals a diverse phenomenology of light curve dimming shapes, such as skewed and symmetric dimmings with timescales spanning days to years, some of which closely resemble exaggerated versions of KIC 8462852. Our sample reveals no clear periodicity patterns sensitive to ZTF in many of these dippers and no infrared excess or irregular variability. Using archival data collated for this study, we thoroughly investigate several classification scenarios and hypothesize that the mechanisms of such dimming events are either driven by circumstellar clumps or occultations by stellar/sub-stellar companions with disks. Our study marks a significant step forward in understanding main-sequence dipper stars.