Optical multicolor polarization observations in the region of the open cluster NGC 5749
| Autor: | R. Martínez, M. M. Vergne, Carlos Feinstein |
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| Rok vydání: | 2006 |
| Předmět: |
Open clusters and associations: individual: NGC 5749
Physics Ciencias Astronómicas Open clusters Ciencias Físicas Astronomy and Astrophysics Optical polarization Champ magnetique purl.org/becyt/ford/1.3 [https] Astrophysics purl.org/becyt/ford/1 [https] Astronomía individual: NGC 5749 [Open clusters and associations] Interstellar medium Space and Planetary Science Polarimetry dust extinction [ISM] ISM: dust extinction CIENCIAS NATURALES Y EXACTAS Optical observation |
| Zdroj: | SEDICI (UNLP) Universidad Nacional de La Plata instacron:UNLP CONICET Digital (CONICET) Consejo Nacional de Investigaciones Científicas y Técnicas instacron:CONICET |
| ISSN: | 1432-0746 0004-6361 |
| Popis: | We present (UBVRI) multicolor linear polarimetric data for 31 of the brightest stars in the area of the open cluster NGC 5749 considered to study the properties of the interstellar medium (ISM) towards the cluster. Our data yield a mean polarization percentage of Pv ∼ 1.7%, close to the polarization value produced by the ISM with normal efficiency (P(%) = 3.5E (B-V)0.8) for a mean color excess of EB-V = 0.42. The mean angle of polarization vectors, θ = 74°, agrees quite well with the expected angle produced by dust particles aligned in the direction of the galactic disk (and the magnetic field) in the region. Our analysis indicates that the visual absorption affecting the stars in NGC 5749 is partially produced by a dust layer located up to 300 pc from the Sun and also by a second layer of dust closer to the cluster (located at least at 700 pc). The observed photometry and our polarization data are consistent with the existence of dust within the cluster. We also show in this work how polarimetry could be an excellent technique for identifying nonmember stars. Facultad de Ciencias Astronómicas y Geofísicas |
| Databáze: | OpenAIRE |
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