Volume 553, May 2013
|Number of page(s)||5|
|Section||Stellar structure and evolution|
|Published online||30 April 2013|
Near-infrared variability in the star-forming region RCW 38⋆
1 Astronomisches Institut, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany
2 Instituto de Astronomía, Universidad Católica del Norte, Antofagasta, Chile
Received: 30 August 2012
Accepted: 11 March 2013
Aims. We want to study the content of young stellar objects in the RCW 38 cluster by means of multi-epoch variability studies.
Methods. We performed a three-month near-infrared (NIR) monitoring campaign of the young cluster RCW 38 using the 80 cm IRIS telescope near Cerro Armazones, Chile. Variability data with a median sampling of 1 day was gathered for 1026 sources, while a total of 3433 sources in JHK could be studied in the co-added, deep images with a completeness limit of K < 15 mag.
Results. We find that 139 sources were identified as variable with amplitudes above 10% in H and K, and 47% of these variables have been classified as candidate young stars by previous X-ray and mid-infrared studies. Although the majority of the variable sources show no K-excess, their high extinction and concentration towards the cluster center, together with their irregular variability behavior, suggest that they are also candidate young stellar objects. Most of them are likely low-mass sources with variability amplitudes typical of T Tauri stars. The majority of previously suggested OB candidates appear to be intermediate-mass pre-main sequence sources on the basis of their JHK properties.
Conclusions. NIR variability is an efficient tool for detecting new, embedded, young stellar objects that have escaped previous X-ray and mid-infrared studies.
Key words: stars: formation / stars: pre-main sequence / stars: variables: T Tauri, Herbig Ae/Be / stars: early-type / stars: late-type / open clusters and associations: individual: RCW 38
Full Tables 1 and 2 are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (22.214.171.124) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/553/A48
© ESO, 2013
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.