WISE color and variability study of SPICY YSOs

In this study, we present an infrared variability analysis of a large sample of over 20,000 candidate YSOs, using data from the ALLWISE and NEOWISE surveys, which span around a decade with a 6 month cadence. We applied Lomb-Scargle periodogram analysis and linear fitting to the light curves, classifying them into distinct categories: secular (linear, curved, and periodic) and stochastic (burst, drop, and irregular).

Our findings show that 5467 (26.2%{\pm}0.3%) of the sources exhibit variability, with most (19.7%{\pm}0.3%) showing irregular variations, followed by curved and periodic variations. In addition, 235 burst sources and 122 drop sources were identified. Variability is more pronounced in Class I sources with a higher fraction of variables (36.3%{\pm}0.6%) compared to Class II (22.1%{\pm}0.4%) and Class III (22.5%{\pm}1.0%) sources.