INVESTIGADORES
PIATTI Andres Eduardo
artículos
Título:
BVI photometry and integrated spectroscopy of the very young open clusters Ruprecht 119, NGC 6318 and BH 245
Autor/es:
PIATTI, ANDRÉS E.; CLARIA OLMEDO, JUAN JOSÉ; BICA, EDUARDO
Revista:
ASTRONOMY AND ASTROPHYSICS
Referencias:
Año: 2000 vol. 362 p. 959 - 967
ISSN:
0004-6361
Resumen:
We present CCD BVI observations obtained for stars in the fields of the
unstudied or poorly studied open clusters Ruprecht 119, NGC 6318, and BH
245 projected close to the direction towards the Galactic centre. We
measured V magnitude and B-V and V-I colours for about 600 stars
reaching down to V ~ 19 mag. From the analysis of the colour magnitude
diagrams, we confirmed the physical reality of the clusters and derived
their reddening, distance and age for the first time. In addition, we
obtained flux-calibrated integrated spectra in the range 3500-9200
Å for the cluster sample. Using the equivalent widths of the
Balmer lines and comparing the cluster spectra with template spectra we
derive both foreground reddening and age. The photometric and
spectroscopic results reveal that the three studied objects are very
young open clusters with ages ranging between 10 and 15 Myr, which have
already undergone the HII region evolutionary phase and are dominated by
the upper MS stars. The clusters, located between 1.1 kpc and 3.3 kpc
from the Sun, are affected by different amounts of interstellar visual
absorption (2.4 <= A_v <= 7.0). In particular, BH 245 turned out
to be a highly reddened open cluster located at a distance of scarcely
1.1 kpc.