Polarimetría multicolor de 47 Tuc

FORTE, J. C.; BASSINO, L. P.; CELLONE, S. A.; MÉNDEZ, M.; PELLIZZA, L. J.; VEGA, E. I.

Gonnet

Congreso; 42a. Reunión Anual AAA; 1998

AAA

We present a polarimetric study of stars belonging to the globularcluster 47 Tucanae (NGC 104) as well as from its nucleus (integrated),which is based on observations obtained in September 1997 with the newphotopolarimeter CASPROF from CASLEO. About 90 stars observed with the Vfilter and the nucleus with UBVRI have been reduced and the analysisshows some interesting results. For instance, the behaviour of thepolarization vectors of the faintest stars suggests the existence oflight polarized by ``scattering''. The presence of an ultraviolet``background'' more extended than the one of stellar light may berelated to this behaviour too. In a previous search we have detectedthat Variable No 13 shows a strong dependence of thepolarization with wavelength which is characteristic of stars with dustyenvelopes. This object is a good candidate to become a progenitor of theplanetary nebulae phase.