CCD Washington Photometry of Ten Open Clusters or Candidates Projected Close to the Galactic Plane

J.J. CLARIÁ; M.C. PARISI; PALMA, T.; AHUMADA, A. V.; OVIEDO C.G.

ACTA ASTRONOMICA

COPERNICUS FOUNDATION POLISH ASTRONOMY

Año: 2019

0001-5237

We present high-quality CCD photometry in the Washington systemC and T1 passbands down to T1≈19.5 mag in the fields often Galactic open clusters or candidates projected close to the Galacticplane, namely: ESO 313-SC03, BH 54, Ruprecht 87, ESO 129-SC32,BH 217, Collinder 347, Basel 5, Ruprecht 144, Archinal 1 andBerkeley 82. Four of these objects are located toward the Galacticcenter within a solid angle of 21°. No photoelectric or CCDphotometry in the optical domain has been so far reported for five ofthese objects. Cluster radii are estimated from radial density profilesin the cluster fields. Using the cluster Washington (C-T1,T1)color-magnitude diagrams, statistically cleaned from field starcontamination, we estimate reddening, heliocentric distance and age ofthe clusters by fitting Padova theoretical isochrones computed for theWashington system. In all cases, the best fittings were obtained withnearly solar metal content isochrones. Both radial density profiles andcolor-magnitude diagrams show that we are dealing with real openclusters, except for Ruprecht 87 and Archinal 1 that are found to beprobably not physical systems. Differential reddening appears to bepresent across the fields of ESO 313-SC03, ESO 129-SC32, BH 217,Collinder 347 and Basel 5. The studied open clusters are located atd☉=1.0-5.0 kpc from the Sun and at Galactocentric distancesRGC=6.0-10.6 kpc, with meanreddening E(B-V) in the range of 0.10-1.30 mag and agesbetween 5 Myr (Collinder 347) and ≈1000 Myr(Basel 5). The estimated linear cluster radii are in the range of0.4-3.2 pc. In general terms, the results obtained show fairlygood agreement with previous photometric results. In some clusters,however, considerable differences are found between the presentresults and previous ones determined using near-infrared photometricdata. The current study provides new open cluster parameters and somerevisions to the open cluster catalogs.