1 Introduction

Cataclysmic variables (CVs) are close binary systems in which mass is transferred from a red dwarf star that fills its Roche lobe onto a white dwarf (WD). Intermediate polars (or DQ Her systems) are a subclass of magnetic cataclysmic variables with an asynchronously rotating ( $P_{\rm spin}< P_{\rm orb}$) magnetic white dwarf (Patterson 1994; Warner 1995). The accretion flow from the red dwarf star forms an accretion disk around the white dwarf, and this disk is disrupted by the magnetic field close to the white dwarf. Within the magnetospheric radius, the material is channelled towards the magnetic polar regions of the white dwarf (Rosen et al. 1988).

The recently discovered pulsating X-ray source 1WGAJ1958.2+3232 (Israel et al. 1998) was announced as a new Intermediated Polar (IP) by Negueruela et al. (2000) from spectral observations. Strong modulations of this source in X-rays were obtained from ROSAT PSPC ($721\pm14$ s) and a more accurate value $734\pm1$ s from ASCA are presented by Israel et al. (1998) and Israel et al. (1999). Photometric observations of the optical counterpart of 1WGAJ1958.2+3232 exhibited strong optical variations, compatible with the X-ray ($\sim$12 min) period (Uslenghi et al. 2000). This modulation was interpreted as evidence of a spin period of the WD in this close binary system.

In this paper we present the results of new photometric and spectral observations of this system.