Identification of Orbital Eclipses in LAMOST J024048.51+195226.9, a Candidate AE Aqr-type Cataclysmic Variable Star

TL;DR

This study refines the orbital period of LAMOST J024048.51+195226.9, a candidate AE Aqr-type cataclysmic variable star, and reports a shallow eclipse that could provide insights into the magnetic propeller mechanism.

Contribution

The paper identifies a previously unrecognized eclipse in a candidate AE Aqr system, offering a new observational feature to study the magnetic propeller phenomenon.

Findings

Refined orbital period measurement for LAMOST J024048.51+195226.9

Detection of a shallow eclipse in the system

Potential to study the magnetic propeller mechanism through eclipse observations

Abstract

AE Aqr objects are a class of cataclysmic variable stars in which the rapidly rotating magnetosphere of the white dwarf (WD) primary centrifugally expels most infalling gas before it can accrete onto the WD. The expulsion of the accretion flow via this "magnetic propeller" extracts angular momentum from the WD and produces large-amplitude, aperiodic flares in optical photometry. The eponymous AE Aqr is the only confirmed member of this class of object, but recently, Thorstensen (2020) discovered a candidate AE Aqr system: LAMOST J024048.51+195226.9. Using survey photometry, we measure a refined orbital period for this system and identify a shallow, previously unrecognized eclipse during which the system's frequent AE Aqr-like flaring episodes cease. A dedicated follow-up study is still necessary to test the proposed AE Aqr classification for LAMOST J024048.51+195226.9, but should it be confirmed, the eclipse of its flare-production region will offer a new means of studying the magnetic propeller phenomenon.