The highly polarized open cluster Trumpler 27

We have carried out multicolor linear polarimetry (U BV RI) of the brightest stars in the area of the open cluster Trumpler 27. Our data show a high level of polarization in the stellar light with a considerable dispersion, from P = 4% to P = 9.5%. The polarization vectors of the cluster members app...

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Detalles Bibliográficos
Autores: Feinstein Baigorri, Carlos, Baume, Gustavo Luis, Vázquez, Rubén Ángel, Niemelä, Virpi Sinikka, Cerruti, Miguel Ángel
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2000
País:Argentina
Institución:Universidad Nacional de La Plata
Repositorio:SEDICI (UNLP)
Idioma:inglés
OAI Identifier:oai:sedici.unlp.edu.ar:10915/84909
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/84909
Access Level:acceso abierto
Palabra clave:Ciencias Astronómicas
Dust, extinction
Open clusters and associations: individual (Trumpler 27)
Descripción
Sumario:We have carried out multicolor linear polarimetry (U BV RI) of the brightest stars in the area of the open cluster Trumpler 27. Our data show a high level of polarization in the stellar light with a considerable dispersion, from P = 4% to P = 9.5%. The polarization vectors of the cluster members appear to be aligned. Foreground polarization was estimated from the data of some nonmember objects, for which two different components were resolved: the first one associated with a dust cloud close to the Sun producing P<SUB>λmax</SUB> = 1.3% and θ = 146°, and a second component, the main source of polarization for the cluster members, originating in another dust cloud, which polarizes the light in the direction of θ = 29°.5. From a detailed analysis, we found that the two components have associated values E<SUB>B-V</SUB> < 0.45 for the first one and E<SUB>B-V</SUB> > 0.75 for the other. Due the difference in the orientation of both polarization vectors, almost 90° (180° at the Stokes representation), the first cloud (θ ∼ 146°) depolarizes the light strongly polarized by the second one (θ ∼ 29°.5).