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11 papers found.
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Fundamental parameters of the highly reddened young open clusters Westerlund 1 and 2

We study the compact open clusters Westerlund 1 (BH 197) and Westerlund 2. We present CCD integrated spectroscopy for both clusters, and CCD imaging in the V and I bands for the former one. So far, Westerlund 1 is possibly the most reddened open cluster studied in detail (). It has an age of 8 ± 3 Myr and a distance from the Sun of  kpc. For Westerlund 2 we derive a visual...

Membership, binarity and metallicity of red giants in the southern open cluster NGC 2354

We present new Coravel radial-velocity observations and photoelectric photometry in the UBV, DDO and Washington systems for a sample of red giant candidates in the field of the intermediate-age open cluster NGC 2354. Photometric membership probabilities show very good agreement with those obtained from Coravel radial velocities. The analysis of the photometric and kinematical...

Improvements on the fundamental parameters of the open cluster Tombaugh 1 through Washington system photometry

We present CCD photometry in the Washington system C and T1 passbands down to  mag in the field of Tombaugh 1, a little studied open cluster located in the third Galactic quadrant. We measured T1 magnitudes and colours for a total of 1351 stars distributed throughout an area of . A cluster radius of was estimated from star counts in 100-pixel a side boxes distributed throughout...

Photometric and Coravel observations of red giant candidates in three open clusters: membership, binarity, reddening and metallicity

Aims.We present new CORAVEL radial-velocity observations and photoelectric photometry in the and  systems for a sample of potential members of the red-giant branches of NGC 6192, NGC 6208 and NGC 6268, three open clusters projected close to the Galactic center direction. We also examine the properties of a sample of 42 inner disk open clusters projected towards almost the same...

IC 2395 and BH 47: Only one open cluster in the Vela constellation

We report UBV photoelectric photometry for 273 stars in the fields of the open clusters IC 2395 and BH 47. Our postulate is that, rather than two different clusters in this region of Vela, there is only one, which we call . The cluster is centered at about , (2000), its angular diameter being ~. The analysis of the photometric data yields 61 probable cluster members and 16...

Multicolour photometry and Coravel observations of stars in the southern open cluster IC 2488

We present new UBV photoelectric observations of 119 stars in the field of the southern open cluster IC 2488, supplemented by DDO and Washington photometry and Coravel radial velocities for a sample of red giant candidates. Nearly 50% of the stars sampled – including three red giants and one blue straggler – are found to be probable cluster members. Photometric membership...

Integrated spectral study of reddened globular clusters and candidates

This paper presents integrated spectra in the range 6700 - 9500 for 20 Galactic globular clusters (and candidates) in the bulge and 5 others projected on the Galactic disk ( and ). Most of them are considerably reddened and are among those least studied in the literature. We derive reddening and metallicity from flux-calibrated spectra, thus providing independent information of...

Photometric study of the open cluster NGC 2323

UBV photoelectric photometry for 175 stars in the field of the southern open cluster NGC 2323, supplemented by DDO photometry of 5 probable giants, is presented. The analysis of the photometric data yields 109 probable members; one of them being a red giant, and 3 possible members. The reddening across the cluster is slightly variable and the mean value . The apparent cluster...

Integrated spectral properties of 7 galactic open clusters

This paper presents flux-calibrated integrated spectra in the range 3600-9000 Å for 7 concentrated, relatively populous Galactic open clusters. We perform 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. For five...

Spectroscopic analysis of the candidate globular clusters NGC 1928 and 1939 in the Large Magellanic Cloud

The integrated spectral properties in the range 3600–6700 Å of the candidate old clusters NGC 1928 and 1939 in the LMC bar are compared with those of old- and intermediate-age reference LMC clusters, the properties of which are better established. It has been possible to infer the age of the sample clusters by means of absorption features and the continuum distribution, in...

Blue–violet spectral evolution of young Magellanic Cloud clusters

We study the integrated spectral evolution in the blue–violet range of 97 blue star clusters in the Magellanic Clouds, from those associated with gas emission to those as old as a few hundred Myr. Some clusters are dominated by the flux of those massive stars that pass through evolutionary stages such as Wolf–Rayet, Luminous Blue Variable, Be, and supergiant stars of different...