Two highly reddened young open clusters located beyond the Sagittarius arm

We present the results of CCD BVI Johnson-Cousins photometry down to V ∼ 19 mag in the regions of the unstudied stellar groups Pismis 23 and BH 222, both projected close to the direction towards the Galactic centre. We measured V magnitude and B - V and V - I colours for a total of 928 stars in fiel...

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Detalles Bibliográficos
Publicado: 2002
Materias:
Open clusters and associations: general
Open clusters and associations: individual: Pismis 23, BH 222
Techniques: photometric
Bifurcation (mathematics)
Charge coupled devices
Distance measurement
Galaxies
Photometry
Sun
Colour-magnitude diagrams
Galactic centre
Johnson-Cousins photometry
Open clusters
Pismis 23
Sagittarius arm
Astrophysics
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046361_v388_n1_p179_Piatti
http://hdl.handle.net/20.500.12110/paper_00046361_v388_n1_p179_Piatti
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00046361_v388_n1_p179_Piatti
record_format dspace
spelling paper:paper_00046361_v388_n1_p179_Piatti2023-06-08T14:27:28Z Two highly reddened young open clusters located beyond the Sagittarius arm Open clusters and associations: general Open clusters and associations: individual: Pismis 23, BH 222 Techniques: photometric Bifurcation (mathematics) Charge coupled devices Distance measurement Galaxies Photometry Sun Colour-magnitude diagrams Galactic centre Johnson-Cousins photometry Open clusters Pismis 23 Sagittarius arm Astrophysics We present the results of CCD BVI Johnson-Cousins photometry down to V ∼ 19 mag in the regions of the unstudied stellar groups Pismis 23 and BH 222, both projected close to the direction towards the Galactic centre. We measured V magnitude and B - V and V - I colours for a total of 928 stars in fields of about 4′ × 4′. Pismis 23 is conclusively a physical system, since a clear main sequence and other meaningful features can be seen in the colour-magnitude diagrams. The reality of this cluster is also supported by star counts carried out within and outside the cluster field. For Pismis 23 we derive colour excesses E(B-V) = 2.0 ± 0.1 and E(V-I) = 2.6 ± 0.1, a distance from the Sun of 2.6 ± 0.6 kpc (Z = -19 pc) and an age of 300 ± 100 Myr (assuming solar metal content). BH222 appears to be young open cluster formed by a vertical main sequence and by a conspicuous group of luminous, typically red supergiant stars. We derived for this cluster a colour excess of E(V-I) = 2.4 ± 0.2, a distance from the Sun of 6.0 ± 2.7 kpc (Z = -46 pc) and an age of 60 ± 30 Myr. The resulting reddening and distance estimates place these two young objects among the most reddened and distance open clusters known in the direction towards the Galactic centre. They are located beyond the Sagittarius arm, close to the direction where this arm probably bifurcates into two arms. 2002 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046361_v388_n1_p179_Piatti http://hdl.handle.net/20.500.12110/paper_00046361_v388_n1_p179_Piatti
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Open clusters and associations: general
Open clusters and associations: individual: Pismis 23, BH 222
Techniques: photometric
Bifurcation (mathematics)
Charge coupled devices
Distance measurement
Galaxies
Photometry
Sun
Colour-magnitude diagrams
Galactic centre
Johnson-Cousins photometry
Open clusters
Pismis 23
Sagittarius arm
Astrophysics
spellingShingle Open clusters and associations: general
Open clusters and associations: individual: Pismis 23, BH 222
Techniques: photometric
Bifurcation (mathematics)
Charge coupled devices
Distance measurement
Galaxies
Photometry
Sun
Colour-magnitude diagrams
Galactic centre
Johnson-Cousins photometry
Open clusters
Pismis 23
Sagittarius arm
Astrophysics
Two highly reddened young open clusters located beyond the Sagittarius arm
topic_facet Open clusters and associations: general
Open clusters and associations: individual: Pismis 23, BH 222
Techniques: photometric
Bifurcation (mathematics)
Charge coupled devices
Distance measurement
Galaxies
Photometry
Sun
Colour-magnitude diagrams
Galactic centre
Johnson-Cousins photometry
Open clusters
Pismis 23
Sagittarius arm
Astrophysics
description We present the results of CCD BVI Johnson-Cousins photometry down to V ∼ 19 mag in the regions of the unstudied stellar groups Pismis 23 and BH 222, both projected close to the direction towards the Galactic centre. We measured V magnitude and B - V and V - I colours for a total of 928 stars in fields of about 4′ × 4′. Pismis 23 is conclusively a physical system, since a clear main sequence and other meaningful features can be seen in the colour-magnitude diagrams. The reality of this cluster is also supported by star counts carried out within and outside the cluster field. For Pismis 23 we derive colour excesses E(B-V) = 2.0 ± 0.1 and E(V-I) = 2.6 ± 0.1, a distance from the Sun of 2.6 ± 0.6 kpc (Z = -19 pc) and an age of 300 ± 100 Myr (assuming solar metal content). BH222 appears to be young open cluster formed by a vertical main sequence and by a conspicuous group of luminous, typically red supergiant stars. We derived for this cluster a colour excess of E(V-I) = 2.4 ± 0.2, a distance from the Sun of 6.0 ± 2.7 kpc (Z = -46 pc) and an age of 60 ± 30 Myr. The resulting reddening and distance estimates place these two young objects among the most reddened and distance open clusters known in the direction towards the Galactic centre. They are located beyond the Sagittarius arm, close to the direction where this arm probably bifurcates into two arms.
title Two highly reddened young open clusters located beyond the Sagittarius arm
title_short Two highly reddened young open clusters located beyond the Sagittarius arm
title_full Two highly reddened young open clusters located beyond the Sagittarius arm
title_fullStr Two highly reddened young open clusters located beyond the Sagittarius arm
title_full_unstemmed Two highly reddened young open clusters located beyond the Sagittarius arm
title_sort two highly reddened young open clusters located beyond the sagittarius arm
publishDate 2002
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046361_v388_n1_p179_Piatti
http://hdl.handle.net/20.500.12110/paper_00046361_v388_n1_p179_Piatti
_version_ 1768542765870743552

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