Enrojecimientos y edades de 4 cúmulos abiertos, débiles y compactos del brazo espiral de Carina

AHUMADA, A.V.; CLARIA OLMEDO, JUAN JOSÉ; BICA, EDUARDO; DUTRA, C; PIATTI, ANDRÉS E.

Tucumán

Congreso; Reunión Anual de la Asoc. Argentina de Astronomía; 2000

Based on observations carried out at CASLEO (San Juan), we present flux-calibrated integrated spectra in the range 3600-6800 Å, of four faint and compact open clusters projected towards the Carina spiral feature, namely: Hogg 11, Hogg 12, Pismis 17 and Bochum 12. We performed simultaneous estimates of age and foreground interstellar reddening by comparing the continuum distribution and line strengths of the cluster spectra with those of template cluster spectra with known parameters. Hogg 11 and Pismis 17 were found to be young open clusters (age ≈ 3-6 Myrs), while Hogg 12 and Bochum 12 are moderately young (100 and 300 Myrs, respectively). The clusters are affected by variable visual absorption Av, ranging from 0.12 mag in Hogg 12 to about 1.0 mag in Bochum 12. Hogg 11 has an internal reddening of about 0.1 mag and is physically related to the stellar association Car OB2 or to its extension (Cr 240). Pismis 17 is associated to an HII region, it has an internal reddening of ≈ 0.3 mags, and it is not physically related to Car OB2.