EDP Sciences
Free access
Volume 502, Number 2, August I 2009
Page(s) 559 - 567
Section Galactic structure, stellar clusters, and populations
DOI http://dx.doi.org/10.1051/0004-6361/200911853
Published online 27 May 2009
A&A 502, 559-567 (2009)
DOI: 10.1051/0004-6361/200911853

The stellar population of the star-forming region G61.48+0.09

A. Marín-Franch1, A. Herrero1, 2, A. Lenorzer1, F. Najarro3, S. Ramirez1, A. Font-Ribera1, and D. Figer4

1  Instituto de Astrofísica de Canarias, 38200 La Laguna, Tenerife, Spain
    e-mail: amarin@iac.es
2  Departamento de Astrofisica, Universidad de La Laguna, Spain
3  Departamento de Astrofisica Molecular e Infrarroja, IEM, CSIC, Madrid, Spain
4  Rochester Institute of Technology, Rochester, NY, USA

Received 16 February 2009 / Accepted 21 April 2009

Context. We present the results of a near-infrared photometric and spectroscopic study of the star-forming region G61.48+0.09.
Aims. The purpose of this study is to characterize the stellar content of the cluster and to determine its distance, extinction, age, and mass.
Methods. The stellar population was studied by using color–magnitude diagrams to select twenty promising cluster members, for which follow-up spectroscopy was done. The observed spectra allowed a spectral classification of the stars.
Results. Two stars have emission lines, twelve are G-type stars, and six are late-O or early-B stars.
Conclusions. The cluster's extinction varies from $A_{K_{\rm S}} = 0.9$ to $A_{K_{\rm S}} = 2.6$, (or $A_{V} \sim 8$ to $A_{V} \sim 23$). G61.48+0.09 is a star-forming region located at $2.5\pm0.4$ kpc. The cluster is younger than 10 Myr and has a minimum stellar mass of $1.5\pm 0.5 \times 10 ^{3}$ $M_\odot$. However, the actual total mass of the cluster remains undetermined, as we cannot see its whole stellar content.

Key words: stars: early-type -- Galaxy: structure -- infrared: stars -- stars: Hertzprung-Russel (HR) and C-M diagrams -- Galaxy: open clusters and associations: andividual: G61.48+0.09

© ESO 2009