Forum Springer Astron. Astrophys.
Forum Whats New Search Orders

Astron. Astrophys. 337, L39-L42 (1998)

Next Section Table of Contents

Letter to the Editor

Phase variability in the optical polarization of GRO J1655-40

M. Gliozzi 1, G. Bodo 2, G. Ghisellini 3, F. Scaltriti * 2 and E. Trussoni 2

1 Dipartimento di Fisica Generale dell'Università, Via P. Giuria 1, I-10125 Torino, Italy
2 Osservatorio Astronomico di Torino, Strada dell'Osservatorio 20, I-10025 Pino Torinese (TO), Italy
3 Osservatorio Astronomico di Milano, Sezione di Merate, Via Bianchi 46, I-22055 Merate (MI), Italy

Received 25 March 1998 / Accepted 3 August 1998


We present the results of the new optical polarimetric observations of the superluminal source GRO J1655-40, carried out in July 1997, with the multichannel photopolarimeter of the Torino Observatory, using the 2.15-m telescope of Complejo Astronomico El Leoncito (Argentina). The observed amount of polarization shows (mainly in the V and I bands) oscillations which are consistent with the orbital period of the system. This gives information about physical and geometrical properties of the binary system and confirms that the optical continuum is intrinsically polarized. The origin of the polarized flux is likely to be related to electron scattering of photons from the accretion disk.

Key words: polarization – stars: individual: GRO J1655 – 40 – stars: novae, cataclysmic variables

* Visiting Astronomer, Complejo Astronomico El Leoncito operated under agreement between the Consejo Nacional de Investigaciones Cientificas y Tecnicas de la Republica Argentina and the National Universities of La Plata, Cordoba and San Juan.

Send offprint requests to: G. Bodo

SIMBAD Objects


Next Section Table of Contents

© European Southern Observatory (ESO) 1998

Online publication: August 27, 1998