Taichi, The various hypotheses are discussed by Dahm and Hillenbrand( https://arxiv.org/abs/2010.02996). We are now following this object intensively, since on short timescales of hours we also detect variability of some kind. Siegfried Op vr 12 nov. 2021 om 02:57 schreef Taichi Kato < tkato@kusastro.kyoto-u.ac.jp>:

V347 Aur light curve

ASAS-SN data:

https://asas-sn.osu.edu/sky-patrol/coordinate/9d1c40e3-d651-420c-8aa5-e8a8f2...

The events look nearly periodic. Caused by an eccentric orbiting secondary?