Abstract:
We present a detailed analysis of the long-term photometric and spectroscopic evolution of V1180 Cas over a
decade, aiming to identify the dominant mechanisms behind its variability. We combine multiband light curves
from 1999 to 2025 with over 30 epochs of optical to near-infrared (NIR) spectroscopy (0.5–2.5 μm), analyzing
variability patterns, color behavior, and emission line diagnostics. We investigate the temporal evolution of accretion and outflow indicators and their correlation with photometric states. The light curve reveals a transition
from sporadic early dimming events to a quasi-periodic pattern since 2018, with 11 major dips showing asymmetry and stochastic substructure. Color–magnitude diagrams show classic UXor-like blueing during deep
minima, while NIR and mid-infrared color changes indicate thermal evolution of the disk. Spectroscopic analysis
reveals persistent hydrogen, Ca II, He I, and forbidden line emission. Accretion diagnostics track photometric
variability, and forbidden lines often intensify during dips, implying a physical link between extinction and
outflows. Estimated accretion rates range from ∼10−8 to 10−7 M⊙ yr−1 ; the outflow rate and density diagnostics are consistent with disk winds and shock-excited jets. V1180 Cas demonstrates dual-mode variability driven by both variable circumstellar extinction and episodic accretion events. The hybrid UXor/EXor behavior, combined with evolving disk signatures and persistent outflows, suggests a young stellar object undergoing coupled accretion–extinction–outflow evolution. Continued monitoring will be essential to fully resolve the physical processes shaping its variability.
