Early-type stars in the open cluster NGC 4852

The southern open cluster NGC 4852 was re-observed in the <i>UBVRI</i> passbands to refine its intrinsic fundamental parameters. An extended spectral coverage was also undertaken aimed at obtaining a clear picture of the kind of stars inhabiting the cluster upper main sequence. We detect...

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Detalles Bibliográficos
Autores principales: Ahumada, J. A., Giorgi, Edgard Ervar Salvador, Solivella, Gladys Rebeca, Vázquez, Rubén Ángel
Formato: Articulo
Lenguaje:Inglés
Publicado: 2011
Materias:
Ciencias Astronómicas
Galaxy: structure
Open clusters and associations: general
Open clusters and associations: individual: NGC 4852
Stars: early-type
Stars: emission-line, Be
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83999
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-83999
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Astronómicas
Galaxy: structure
Open clusters and associations: general
Open clusters and associations: individual: NGC 4852
Stars: early-type
Stars: emission-line, Be
spellingShingle Ciencias Astronómicas
Galaxy: structure
Open clusters and associations: general
Open clusters and associations: individual: NGC 4852
Stars: early-type
Stars: emission-line, Be
Ahumada, J. A.
Giorgi, Edgard Ervar Salvador
Solivella, Gladys Rebeca
Vázquez, Rubén Ángel
Early-type stars in the open cluster NGC 4852
topic_facet Ciencias Astronómicas
Galaxy: structure
Open clusters and associations: general
Open clusters and associations: individual: NGC 4852
Stars: early-type
Stars: emission-line, Be
description The southern open cluster NGC 4852 was re-observed in the <i>UBVRI</i> passbands to refine its intrinsic fundamental parameters. An extended spectral coverage was also undertaken aimed at obtaining a clear picture of the kind of stars inhabiting the cluster upper main sequence. We detected an unusual number of B-type stars including a new weak-emission Be star that raises to three the number of confirmed emission objects known in the cluster area. Our analysis, however, is conclusive in that none of them belongs to the cluster. With the new data set, we improved the fundamental parameters of NGC 4852: it is little bit farther than formerly assumed; the reddening, which increases smoothly with the distance, is lower than early estimates; and more importantly, it is really a young object of nearly 40-60Myr, contrary to the age of 200 Myr stated before. By means of spectroscopic parallaxes we secured the star distances, finding a good agreement between spectroscopic and zero-age main-sequence fitting distances, within the errors. The spatial distribution of the stars allows us to infer that NGC 4852 is the final, closer to the Sun, structure of a star-forming region and that a distant group of early-B-type stars, located immediately beyond the cluster, seems to be part of an extended OB association. The three emission stars detected in the region are related to this farther group. Finally, two extremely faint and blue stars were also found in the cluster zone. They have no connection with NGC 4852 but seem to be white-dwarf candidates.
format Articulo
Articulo
author Ahumada, J. A.
Giorgi, Edgard Ervar Salvador
Solivella, Gladys Rebeca
Vázquez, Rubén Ángel
author_facet Ahumada, J. A.
Giorgi, Edgard Ervar Salvador
Solivella, Gladys Rebeca
Vázquez, Rubén Ángel
author_sort Ahumada, J. A.
title Early-type stars in the open cluster NGC 4852
title_short Early-type stars in the open cluster NGC 4852
title_full Early-type stars in the open cluster NGC 4852
title_fullStr Early-type stars in the open cluster NGC 4852
title_full_unstemmed Early-type stars in the open cluster NGC 4852
title_sort early-type stars in the open cluster ngc 4852
publishDate 2011
url http://sedici.unlp.edu.ar/handle/10915/83999
work_keys_str_mv AT ahumadaja earlytypestarsintheopenclusterngc4852
AT giorgiedgardervarsalvador earlytypestarsintheopenclusterngc4852
AT solivellagladysrebeca earlytypestarsintheopenclusterngc4852
AT vazquezrubenangel earlytypestarsintheopenclusterngc4852
bdutipo_str Repositorios
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