WISE color and variability study of SPICY YSOs

The variability of young stellar objects (YSOs) is a crucial tool for understanding the mechanisms driving flux changes. 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. The color (W1-W2) versus magnitude analysis (W2) using linear fitting shows that the "redder-when-brighter" trend is more prevalent (85.4%{\pm}0.5%) among YSOs. In contrast, the "bluer-when-brighter" (BWB) trend is more common in younger sources compared to more evolved ones, having a BWB fraction of 29.0%{\pm}1.1% for Class I to 4.0%{\pm}0.9% for Class III.

Cone search capability for table J/ApJS/278/10/table2 (Variability statistics of individual objects)

Identifier
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/ApJS/278/10
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/278/10
Related Identifier https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/278/10
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/ApJS/278/10
Provenance
Creator Neha S.; Sharma S.
Publisher CDS
Publication Year 2026
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Interstellar medium; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy