We discuss Beppo SAX observations and archive ASCA data of NGC 7679 , a nearby , nearly face-on SB0 galaxy in which starburst and AGN activities coexist .
The X-ray observations reveal a bright ( L _ { 0.1 - 50 keV } \sim 2.9 \times 10 ^ { 43 } erg s ^ { -1 } ) and variable source having a minimum observed doubling/halving time scale of \sim 10 - 20 ksec .
A simple power law with photon index of \Gamma \sim 1.75 and small absorption ( N _ { H } < 4 \times 10 ^ { 20 } cm ^ { -2 } ) can reproduce the NGC 7679 spectrum from 0.1 up to 50 keV .
These X-ray properties are unambiguous signs of Seyfert 1 activity in the nucleus of NGC 7679 .
The starburst activity , revealed by the IR emission , optical spectroscopy and H \alpha imaging , and dominating in the optical and IR bands , is clearly overwhelmed by the AGN in the X-ray band .
Although , at first glance , this is similar to what is observed in other starburst-AGN galaxies ( e.g .
NGC 6240 , NGC 4945 ) , most strikingly here and at odds with the above examples , the X-ray spectrum of NGC 7679 does not appear to be highly absorbed .
The main peculiarity of objects like NGC 7679 is not the strength of their starburst but the apparent optical weakness of the Seyfert 1 nucleus when compared with its X-ray luminosity .
To date NGC 7679 is one of the few Seyfert 1/ Starburst composites for which the broad-band X-ray properties have been investigated in detail .
The results presented here imply that optical and infrared spectroscopy could be highly inefficient in revealing the presence of an AGN in these kinds of objects , which instead is clearly revealed from X-ray spectroscopic and variability investigations .