WISE color and variability study of SPICY YSOs Virtual Observatory Resource

Authors
  1. Neha S.
  2. Sharma S.
  3. Published by
    CDS
Abstract

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.

Keywords
  1. young-stellar-objects
  2. infrared-photometry
  3. two-color-diagrams
  4. variable-stars
Bibliographic source Bibcode
2025ApJS..278...10N
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/278/10
IVOA Identifier IVOID
ivo://CDS.VizieR/J/ApJS/278/10

Access

Web browser access HTML
https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/278/10
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/278/10
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/278/10
IVOA Table Access TAP
https://tapvizier.cds.unistra.fr/TAPVizieR/tap
Run SQL-like queries with TAP-enabled clients (e.g., TOPCAT).
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/278/10/table2?
https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/278/10/table2?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/278/10/table2?

History

2026-03-03T14:02:33Z
Resource record created
2026-03-03T13:13:26Z
Updated
2026-03-03T14:02:33Z
Created

Contact

Name
CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr