VOSA: virtual observatory SED analyzer^*

An application to the Collinder 69 open cluster

¹ Laboratorio de Astrofísica Espacial y Exoplanetas, Centro de Astrobiologia (LAEFF-CAB, INTA-CSIC), European Space Astronomy Center (ESAC), PO Box 78, 28691 Villanueva de la Cañada, Madrid, Spain e-mail: abayo@laeff.inta.es
² SVO Thematic Network, Spain
³ Centre de Recherche Astronomique de Lyon (CRAL), École Normale Supérieure de Lyon, 69364 Lyon, France

Received: 16 June 2008
Accepted: 1 August 2008

Abstract

Context. The physical properties of almost any kind of astronomical object can be derived by fitting synthetic spectra or photometry extracted from theoretical models to observational data.

Aims. We want to develop an automatic procedure to perform this kind of fitting to a relatively large sample of members of a stellar association and apply this methodology to the case of Collinder 69.

Methods. We combine the multiwavelength data of our sources and follow a work-flow to derive the physical parameters of the sources. The key step of the work-flow is performed by a new VO-tool, VOSA. All the steps in this process are done in a VO environment.

Results. We present this new tool, and provide physical parameters such as T_eff, gravity, luminosity, etc. for ~170 candidate members of Collinder 69, and an upper-limit for the age of this stellar association.

Conclusions. This kind of study of star forming regions, clusters, etc. produces a huge amount of data, very tedious to analyse using the traditional methodology. Thus, they are excellent examples of where to apply the VO techniques.