Optical polarization observations in Scorpiu s region: NGC 6124

M. MARCELA VERGNE; CARLOS FEINSTEIN; RUBEN MARTÍNEZ; ANA MARÍA ORSATTI; MARÍA PAULA ALVAREZ

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2009

0035-8711

We present optical multicolour (UBVRI) linear polarimetric data for 46 of the brightest stars in the area of the open cluster NGC 6124, with the aim of studying the properties of the ISM towards the cluster. Our  data yield a mean polarization efficiency of $P_V/E_{B-V}=$3.1$\pm$0.62, a value lower than  the polarization produced by the ISM with normal  efficiency for an average colour excess of $E_{B-V}=0.80$. Also, the polarization shows an orientation of $\theta \sim $8$^\circ$.1 which is notin the direction of the Galactic Disk. We interpreted that  this result is produced by the Lupus Cloud.  Our analysis also indicates that the observed visual extinction in NGC 6124 is caused by the presence of three absorption sheets between the Sun and NGC 6124. The internal scatter in polarization ($\Delta P_V\sim 1.3\%$) and in colour excess ($\Delta E_{B-V}\sim 0.29$ mag) for the members of NGC 6124 seems to be compatible with the presence of an intra-cluster dust component.Only six observed stars show some evidences of intrinsiC polarization in their light. In this work we also show (as in several previous papers) hoW  polarimetry is an excellent technique for identifying non-member stars.