SIMBAD references

ROSAT X-ray and contemporaneous ground-based optical observations of the cataclysmic binary, V795 Her, are presented. The source is detected in the ROSAT PSPC, providing the first constraints on its X-ray spectrum which indicate a modest column of ∼5x10²⁰cm^–2 and that it may have a hard spectral distribution. Although the source is variable in X-rays, no evidence of systematic X-ray temporal variability is found at the 2.6h (radial velocity), 2.8h (optical photometric) or 4.8h (UV C IV and Si IV line intensity) periods previously detected in this star. Fourier analysis does show evidence of broad band power at periods near 15 minutes which most probably reflects the presence of QPO and/or flickering activity. In the optical, the power spectrum is dominated by strong red noise, indicative of flickering, although in some of the observations, a preferred timescale similar to that in the X-ray band may be present. However, we find no significant evidence for any correlated behaviour between the X-ray and optical timeseries. We believe the balance of evidence argues against an intermediate polar classification for V795 Her.