UBVRI C photometry of the open clusters Be 15, Be 80, and NGC 2192 - Astrophysics > Solar and Stellar AstrophysicsReportar como inadecuado

UBVRI C photometry of the open clusters Be 15, Be 80, and NGC 2192 - Astrophysics > Solar and Stellar Astrophysics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: The three open clusters Be 15, Be 80, and NGC 2192 have been observed usingCCD UBVRI C photometry at the San Pedro M\-artir Observatory, M\-exico withinthe framework of our open-cluster survey. The fundamental parameters ofinterstellar reddening, distance, and age have been derived, and also themetallicity for NGC 2192 solar metallicity has been assumed for the othertwo. By shifting the colours of Schmidt-Kaler in the U-B, B-V two-colourdiagram along the appropriate reddening vector, the interstellar reddeningshave been derived as EB-V=0.23+-0.03 mag for Be 15, 1.31+-0.05 for Be 80,and 0.16+-0.03 for NGC 2192. Evidence is shown for a variable interstellarextinction across the cluster Be 80. For NGC 2192 a nicely consistent fit isobtained for both the interstellar reddening and the metallicity Fe-H=-0.31using simultaneously the F-type and red-clump stars. By fitting isochrones tothe observed sequences of these three clusters in various colour-magnitudediagrams of different colour indices, B-V, V-I, or V-R the averages ofdistance moduli and heliocentric distances V-M V o mag; dpc are thefollowing: 10.74+-0.01; 1202 for Be 15, 10.75+-0.01; 1413 for Be 80, and12.7+-0.01; 3467 for NGC 2192, and the averages of the inferred best ageslogage; age Gyr are 8.6+-0.05; 0.4 for Be 80, and 9.15+-0.05; 1.4for NGC 2192; for Be 15 there are two distinct possibilities for the age fit,depending on the membership of three brighter stars, 9.35 or 9.95+-0.05; 2.2or 8.9. The need for spectroscopic observations in Be 15 is emphasized toselect between alternate reddening and age solutions, and for deeper UBVobservations in Be 80 to study in greater detail the variable interstellar, orintracluster, reddening across this cluster.

Autor: M. T. Tapia, W. J. Schuster, R. Michel, C. Chavarría-K., W. S. Dias, R. Vázquez, A. Moitinho

Fuente: https://arxiv.org/


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